### LINCOLN PARK/COTTER URANIUM MILL CAÑON CITY, FREMONT COUNTY, COLORADO

EPA FACILITY ID: COD042167585

SEPTEMBER 9, 2010



# NOVEMBER 9, 2010THE ATSDR PUBLIC HEALTH ASSESSMENT: A NOTE OF EXPLANATION

This Public Health Assessment-Public Comment Release was prepared by ATSDR pursuant to the Comprehensive

Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) section 104 (i)( 6) (42 U.S.C. 9604 (i)(6),

and in accordance with our implementing regulations (42 C.F.R. Part 90). In preparing this document, ATSDR has collected

relevant health data, environmental data, and community health concerns from the Environmental Protection Agency (EPA),

state and local health and environmental agencies, the community, and potentially re sponsible parties, where appropriate.

This document represents the agency’s best efforts, based on currently available information, to fulfill the statutory criteria set

out in CERCLA section 104 (i)(6) within a limited time frame. To the extent possible, it presents an assessment of potential

risks to human health. Actions authorized by CERCLA section 104 (i)(11), or otherwise authorized by CERCLA, may be

undertaken to prevent or mitigate human exposure or risks to human health. In addition, ATSDR will utilize this document to

determine if follow-up health actions are appropriate at this time.

This document has previously been provided to EPA and the affected state in an initial release, as required by CERCLA

section 104 (i) (6) (H) for their informati on and review. Where necessary, it has be en revised in response to comments or

additional relevant information provided by them to ATSDR. This revised document has now been released for a 30-day

public comment period. Subsequent to the public comment period, ATSDR will address all p ublic comments and revise or

append the document as appropriate. The public health assessment will then be reissued. This will conclude the public

health assessment process for this site, un less additional information is obtained by ATSDR which, in the agency’s opinion,

indicates a need to revise or append the conclusions previously issued.

Agency for Toxic Substances and Disease Registry .................................... .T homas R. Frieden, M.D., M.P.H., Adminis trator

Christopher J. Portier, Ph.D., Director

Division of Health Assessment and Consultation........................ .......................William Cibulas, Jr., Ph.D., Director

Sharon Williams-Fleetwood, Ph.D., Deputy Director

Health Promotion and Community Involvement Branch ....................................Hilda Shepeard , Ph.D., M. B.A., Chief

Exposure Investigations and Consultation Branch...... ................................................Susan M. Moore, M.S., Chief

Federal Facilities Assessment Branch...........................

.......................................... .Sandra G. Isaacs, B.S., Chief

Superfund and Program Assessm ent Branch .......................................................................... Richard E. G illig, M.C.P., Chief

Use of trade names is for identification only and does not constitute endorsement by the Public Health Service or the

U.S. Department of Health and Human Services.

Please address comments regarding this report to:

Agency for Toxic Substan ces and Disease Registry

Attn: Records Center

1600 Clifton Road, N.E., MS F-09

Atlanta, Georgia 30333

You May Contact ATSDR Toll Free at

1-800-CDC-INFO or

Visit our Home Page at: http://www.atsdr.cdc.gov

### Lincoln Park/Cotter Uranium Mill Public Comment Release



## PUBLIC HEALTH ASSESSMENT

LINCOLN PARK/COTTER URANIUM MILL

CAÑON CITY, FREMONT COUNTY, COLORADO

EPA FACILITY ID: COD042167585

Prepared by:

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry

Division of Health Assessment and Consultation

Site and Radiological Assessment Branch

This information is distributed by the Agency fo r Toxic Substances and Disease Registry for public

comment under applicable information quality guidel ines. It does not represent and should not be

construed to represent final agen cy conclusions or recommendations.Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment



## Foreword

The Agency for Toxic Substances and Disease Registry, ATSDR, was established by Congress

in 1980 under the Comprehensive Environmental Response, Compensation, and Liability Act

(CERCLA), also known as the Superfund law. This law set up a fund to identify and clean up

hazardous waste sites. The Environmental Protection Agency (EPA) and the individual states

regulate the investigation a nd clean up of the sites.

Since 1986, ATSDR has been required by law to c onduct a public health assessment at each of

the sites on the EPA National Priori ties List. The aim of these eval uations is to find out if people

are being exposed to hazardous substances and, if so, whether that exposure is harmful and

should be stopped or reduced. If appropriate, ATSDR also conducts public health assessments

when petitioned by concerned individuals. Pub lic health assessments are carried out by

environmental and health scientists from ATSD R and from the states with which ATSDR has

cooperative agreements. The public health assess ment process allows ATSDR scientists and

public health assessment cooperative agreement pa rtners flexibility in document format when

presenting findings about the public health impact of hazardous waste sites. The flexible format

allows health assessors to convey to affected populations important public health messages in a

clear and expeditious way.

Exposure: As the first step in the evaluation, ATSD R scientists review environmental data to

see how much contamination is at a site, where it is, and how people might come into contact

with it. Generally, ATSDR does not collect its own environmental sampling data but reviews

information provided by EPA, other government agencies, businesses, and the public. When

there is not enough environmental information ava ilable, the report will indicate what further

sampling data is needed.

Health Effects: If the review of the environmental data shows that people have or could come

into contact with hazardous subs tances, ATSDR scientists evaluate whether or not these contacts

may result in harmful effects. ATSDR recognizes that children, because of their play activities

and their growing bodies, may be more vulnerable to these effect s. As a policy, unless data are

available to suggest otherwise, ATSDR considers children to be more sensitive and vulnerable to

hazardous substances. Thus, the health impact to th e children is considered first when evaluating

the health threat to a community. The health impacts to other high-risk groups within the

community (such as the elderly, ch ronically ill, and pe ople engaging in high risk practices) also

receive special attenti on during the evaluation.

ATSDR uses existing scientific information, which can include the results of medical,

toxicologic and epidemiologic studies and the data collected in disease registries, to evaluate

possible the health effects that may result from e xposures. The science of e nvironmental health is

still developing, and sometimes scie ntific information on the health effects of certain substances

is not available.

Community: ATSDR also needs to learn what people in the area know about the site and what

concerns they may have about its impact on their health. Consequently, throughout the

evaluation process, ATSDR actively gathers in formation and comments from the people who

live or work near a site, including residents of the area, civic lead ers, health professionals, andPublic Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment



### community groups. To ensure that the report resp onds to the community's health concerns, an

early version is also distributed to the public for their commen ts. All the public comments that

related to the document are addressed in the final version of the report.

Conclusions: The report presents conclusions about the public health thr eat posed by a site.

Ways to stop or reduce exposure will then be recommended in the public health action plan.

ATSDR is primarily an advisory agency, so us ually these reports identify what actions are

appropriate to be undertaken by EPA or other responsible parties. Ho wever, if there is an urgent

health threat, ATSDR can issue a public health advisory warn ing people of the danger. ATSDR

can also recommend health education or pilot st udies of health effects, full-scale epidemiology

studies, disease registries, surv eillance studies or research on specific hazardous substances.

Comments: If, after reading this report, you have que stions or comments, we encourage you to

send them to us.

Letters should be a ddressed as follows:

Attention: Rolanda Morrison

ATSDR Records Center (MS F-09)

4770 Buford Hwy, NE

Building 106, Room 2108

Atlanta, GA 30341Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment



## Table of Contents

II. BACKGR OUND

..................................................................................................................... ...................... 5

A. S ITE DESCRIPTION AND OPERATIONAL HISTORY

........................................................................................................... 5

B. R EMEDIAL AND REGULATORY HISTORY

...................................................................................................................... 5

C. D EMOGRAPHICS

................................................................................................................................................. 10

D. L AND USE AND NATURAL RESOURCES

...................................................................................................................... 11

1. Hydrogeology

........................................................................................................................................... 11

2. Geology

..................................................................................................................................................... 11

3. Hydrology

................................................................................................................................................. 12

4. Prevailing Wind Patterns

.......................................................................................................................... 12

E. P AST ATSDR INVOLVEMENT

...................................................................................................................................... 13

III. EVALUATION OF EXPOSURE PATHWAYS

................................................................................................... 15

A. W HAT IS MEANT BY EXPOSURE ?

............................................................................................................................ 15

B. H OW DOES ATSDR DETERMINE WHICH EXPOSURE SITUATIONS TO EVALUATE ?

............................................................... 16

C. I F SOMEONE IS EXPOSED

, WILL THEY GET SICK ?

......................................................................................................... 17

D. W HAT EXPOSURE SITUATIONS WERE EVALUATED FOR RESIDENTS LIVING NEAR THE C OTTER M ILL ?

...................................... 17

1. Exposure to groundwater in Lincoln Park

................................................................................................. 18

2. Contact with soil adjacent to the Cotter Mill and in Lincoln Park

............................................................. 18

a) Contact with soil near the Cotter Mill

.................................................................................................................. 19

b) Contact with soil and sediment in the community of Lincoln Park

...................................................................... 19

3. Contact with surface water downstream from the Cotter Mill

................................................................ 20

4. Exposure from eating locally grown produce

........................................................................................... 20

5. Exposure from breathing windborne dust

................................................................................................ 20

IV. EVALUATION OF ENVIRONMENTAL CONTAMINATION

.............................................................................. 25

A. G ROUNDWATER

................................................................................................................................................. 25

1. Remedial actions for controlling groundwater contamination

................................................................ 25

2. Nature and extent of groundwater contamination in Lincoln Park

.......................................................... 26

a) Wells used for personal consumption

.................................................................................................................. 26

(1) Grand Avenue Well

......................................................................................................................................... 27

b) Wells used to irrigate fruit and vegetable gardens

.............................................................................................. 27

c) Wells used to water livestock

............................................................................................................................... 28

d) Wells used to water lawns

.................................................................................................................................... 29

(1) Well 138

.......................................................................................................................................................... 29

e) Groundwater trends over time

............................................................................................................................ 30

B. S OIL AND SEDIMENT

............................................................................................................................................ 30

1. Background levels

..................................................................................................................................... 30

2. Off

‐ site soil contamination and remediation

............................................................................................ 31

a) The nearest resident

............................................................................................................................................. 32

b) Lincoln Park

.......................................................................................................................................................... 32

(1) Lead in Lincoln Park

......................................................................................................................................... 33

c) Sand Creek

............................................................................................................................................................ 34

d) The Fremont Ditch

................................................................................................................................................ 35

C. S URFACE WATER

................................................................................................................................................ 35

1. Nature and extent of contamination

........................................................................................................ 35

a) Sand Creek

............................................................................................................................................................ 36

b) DeWeese Dye Ditch

.............................................................................................................................................. 37

c) Arkansas River

...................................................................................................................................................... 37

d) Willow Lakes

......................................................................................................................................................... 39

D. L OCALLY GROWN PRODUCE

............................................................................................................................... ... 39

1. Nature and extent of contamination

........................................................................................................ 39

E. A MBIENT A IR

.................................................................................................................................................... 40Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment

1. Nature and extent of air contamination

................................................................................................... 41

a) Ambient Air Monitoring for Radioactive Substances

............................................................................................ 42

(1) Particulate Matter

........................................................................................................................................... 42

(2) Particle

‐ Bound Radionuclides

......................................................................................................................... 43

b) Radon Gas

............................................................................................................................................................. 47

c) Gamma Radiation

................................................................................................................................................. 48

d) Ambient Air Monitoring for non

‐ Radioactive Substances

.................................................................................... 49

(1) Particulate Matter (TSP, PM 10 , and PM 2.5 )

...................................................................................................... 49

(2) Constituents of Particulate Matter

................................................................................................................. 50

V. PUBLIC HEALTH EVALUATION

................................................................................................................... 51

A. I NTRODUCTION

.................................................................................................................................................. 51

B. H OW H EALTH E FFECTS ARE E VALUATED

.................................................................................................................. 51

C. G ROUNDWATER P ATHWAY : P RIVATE WELLS USED FOR PERSONAL CONSUMPTION

.......................................................... 52

1. Molybdenum

............................................................................................................................................. 53

a) Health Evaluation of Molybdenum

....................................................................................................................... 53

b) Additional Comments about Molybdenum in Drinking Water

............................................................................. 55

2. Uranium

.................................................................................................................................................... 55

a) Health Evaluation of Uranium

.............................................................................................................................. 56

D. S OIL P ATHWAY : S URFACE S OIL NEAR C OTTER M ILL AND L INCOLN P ARK

........................................................................ 59

1. Soil Near Cotter Mill

............................................................................................................................... ... 60

a) Arsenic

.................................................................................................................................................................. 60

b) Cadmium

.............................................................................................................................................................. 60

c) Lead

...................................................................................................................................................................... 60

d) Radium

‐ 226

.......................................................................................................................................................... 61

2. Soil in Lincoln Park

.................................................................................................................................... 62

a) Arsenic

.................................................................................................................................................................. 62

E. S URFACE W ATER : S AND C REEK

, D E W EESE D YE D ITCH

, AND THE A RKANSAS R IVER

......................................................... 62

1. Manganese

............................................................................................................................................... 63

2. Molybdenum

............................................................................................................................................. 63

F. H OMEGROWN F RUITS AND V EGETABLES

................................................................................................................. 63

G. A IR P ATHWAY

................................................................................................................................................... 66

VI. COMMUNITY HEALTH CONCERNS

............................................................................................................. 68

VII. CONCLUSIONS

.......................................................................................................................................... 74

VIII. RECOMMENDATIONS

............................................................................................................................... 75

IX. PUBLIC HEALTH ACTION PLAN

.................................................................................................................. 76

X. SITE TEAM

................................................................................................................................................ 77

XI. REFERENCES

............................................................................................................................................. 78

APPENDIX A

‐ TABLES

...................................................................................... ERROR! BOOKMARK NOT DEFINED.

T ABLE 14. W ELL U SE IN L INCOLN P ARK

, 1989

.................................................................................................................. 87

T ABLE 15. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM WELLS USED FOR PERSONAL CONSUMPTION

................................ 90

T ABLE 16. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM BACKGROUND WELLS

............................................................. 92

T ABLE 17. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM THE G RAND A VENUE W ELL

..................................................... 94

T ABLE 18. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM WELLS USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS

............ 95

T ABLE 19. G ROUNDWATER SAMPLING DATA ( RADIONUCLIDES ) FROM WELLS USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS

...... 98

T ABLE 20. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM WELLS USED TO WATER LIVESTOCK

............................................ 99

T ABLE 21. G ROUNDWATER SAMPLING DATA ( RADIONUCLIDES ) FROM WELLS USED TO WATER LIVESTOCK

.................................... 102

T ABLE 22. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM WELLS USED TO WATER LAWNS

.............................................. 103

T ABLE 23. G ROUNDWATER SAMPLING DATA ( RADIONUCLIDES ) FROM WELLS USED TO WATER LAWNS

........................................ 106

T ABLE 24. G ROUNDWATER SAMPLING DATA ( CHEMICALS ) FROM W ELL 138

......................................................................... 107Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment

T ABLE 25. G ROUNDWATER SAMPLING DATA ( RADIONUCLIDES ) FROM W ELL 138

................................................................... 109

T ABLE 26. S URFACE SOIL SAMPLING DATA ( CHEMICALS ) FROM EIGHT ZONES AROUND THE C OTTER M ILL AND FROM L INCOLN P ARK

. 110

T ABLE 27. S URFACE SOIL SAMPLING DATA ( RADIONUCLIDES ) FROM EIGHT ZONES AROUND THE C OTTER M ILL AND FROM L INCOLN P ARK

.............................................................................................................................................................................. 112

T ABLE 28. S URFACE SOIL SAMPLING DATA ( RADIONUCLIDES ) FROM THE COUNTY ROAD AND THE C OTTER U RANIUM M ILL ACCESS ROAD

T ABLE 29. S OIL DATA ( CHEMICALS ) FROM SAMPLES TAKEN BY CDPHE, J ANUARY 2003

.......................................................... 115

T ABLE 30. S OIL DATA ( RADIONUCLIDES ) FROM SAMPLES TAKEN BY CDPHE, J ANUARY 2003

.................................................... 116

T ABLE 35. S URFACE SOIL SAMPLING DATA ( RADIONUCLIDES ) FROM YARDS

, GARDENS

, AND AIR MONITORING LOCATIONS IN L INCOLN .............................................................................................................................................................................. 114

T ABLE 31. S URFACE SOIL SAMPLING DATA FROM 10 AIR MONITORING LOCATIONS

.................................................................. 117

T ABLE 32. S OIL SAMPLING DATA ( CHEMICALS ) FROM LOCATION AS

‐ 212 ( THE N EAREST R ESIDENT )

........................................... 118

T ABLE 33. S OIL SAMPLING DATA ( RADIONUCLIDES ) FROM LOCATION AS

‐ 212 ( THE N EAREST R ESIDENT )

..................................... 119

T ABLE 34. S URFACE SOIL SAMPLING DATA ( CHEMICALS ) FROM LAWNS AND GARDENS IN L INCOLN P ARK

..................................... 120

P ARK

....................................................................................................................................................................... 121

T ABLE 36. S URFACE SOIL DATA ( CHEMICALS ) FROM LAWNS AND GARDENS IN L INCOLN P ARK

.................................................... 122

T ABLE 37. S URFACE SOIL DATA ( RADIONUCLIDES ) FROM LAWNS AND GARDENS IN L INCOLN P ARK

.............................................. 123

T ABLE 38. S EDIMENT SAMPLING DATA ( CHEMICALS ) FROM S AND C REEK

.............................................................................. 124

T ABLE 39. S EDIMENT SAMPLING DATA ( RADIONUCLIDES ) FROM S AND C REEK

........................................................................ 125

T ABLE 40. C HEMICAL SAMPLING FOR THE S AND C REEK C LEANUP P ROJECT

............................................................................ 126

T ABLE 41. S URFACE WATER SAMPLING DATA ( CHEMICALS ) FROM S AND C REEK

...................................................................... 127

T ABLE 42. S URFACE WATER SAMPLING DATA ( RADIONUCLIDES ) FROM S AND C REEK

................................................................ 128

T ABLE 43. S URFACE WATER SAMPLING DATA ( CHEMICALS ) FROM THE D E W EESE D YE D ITCH

.................................................... 129

T ABLE 44. S URFACE WATER SAMPLING DATA ( RADIONUCLIDES ) FROM THE D E W EESE D YE D ITCH

.............................................. 131

T ABLE 45. S URFACE WATER SAMPLING DATA ( CHEMICALS ) FROM THE A RKANSAS R IVER

.......................................................... 132

T ABLE 46. S URFACE WATER SAMPLING DATA ( RADIONUCLIDES ) FROM THE A RKANSAS R IVER

.................................................... 133

T ABLE 47. S AMPLING DATA ( CHEMICALS ) FOR LOCAL AND SUPERMARKET FOODS

.................................................................... 135

T ABLE 48. S AMPLING DATA ( RADIONUCLIDES ) FOR LOCAL AND SUPERMARKET FOODS

............................................................. 136

T ABLE 49. S AMPLING DATA ( CHEMICALS ) FOR LOCAL PRODUCE IRRIGATED WITH CONTAMINATED WELL WATER

............................ 137

T ABLE 50. S AMPLING DATA ( RADIONUCLIDES ) FOR LOCAL PRODUCE IRRIGATED WITH CONTAMINATED WELL WATER

...................... 139

T ABLE 51. C HARACTERISTICS OF C OTTER M ILL ’ S A MBIENT A IR M ONITORING S TATIONS

.......................................................... 139

T ABLE 52. A VERAGE A NNUAL NAT U C ONCENTRATIONS 1979

‐ 2008 ( Μ C I / ML )

...................................................................... 140

T ABLE 53. A VERAGE A NNUAL 230 T H C ONCENTRATIONS 1979

‐ 2008 ( Μ C I / ML )

.................................................................... 141

T ABLE 54. A VERAGE A NNUAL 232 T H C ONCENTRATIONS 2001

‐ 2008 ( Μ C I / ML )

.................................................................... 142

T ABLE 55. A VERAGE A NNUAL 226 R A C ONCENTRATIONS 1979

‐ 2008 ( Μ C I / ML )

.................................................................... 143

T ABLE 56. A VERAGE A NNUAL 210 P B C ONCENTRATIONS 1979

‐ 2008 ( Μ C I / ML )

.................................................................... 144

T ABLE 57. 220 R N / 222 R N C ONCENTRATIONS 2002

‐ 2008 ( P C I / M 3 )

..................................................................................... 145

T ABLE 58. E NVIRONMENTAL TLD M EASUREMENTS

, 1979

‐ 2008 ( μ R/ HR )

.......................................................................... 146

T ABLE 59. TSP A IR C ONCENTRATIONS ( μG / M 3 ) FROM 1969

‐ 1987

................................................................................... 147

T ABLE 60. M ONITORING D ATA FOR C ONSTITUENTS IN TSP (1978

‐ 1987)

........................................................................... 147

APPENDIX B

‐ SITE FIGURES

............................................................................................................................. 149

F IGURE 1. L OCATION OF THE C OTTER M ILL

, L INCOLN P ARK

, AND C AÑON C ITY

....................................................................... 150

F IGURE 2. D EMOGRAPHICS WITHIN 1 MILE OF THE C OTTER M ILL PROPERTY

.......................................................................... 151

F IGURE 3. W IND R OSE FOR C OTTER M ILL

, 2008

............................................................................................................ 152

F IGURE 4. M OLYBDENUM P LUME M AP

......................................................................................................................... 153

F IGURE 5. U RANIUM P LUME M AP

............................................................................................................................... . 154

F IGURE 6. W ELLS IN L INCOLN P ARK USED FOR PERSONAL CONSUMPTION

.............................................................................. 155

F IGURE 7. M OLYBDENUM CONCENTRATIONS IN WELLS USED FOR PERSONAL CONSUMPTION

..................................................... 156

F IGURE 8. D ISSOLVED URANIUM CONCENTRATIONS IN WELLS USED FOR PERSONAL CONSUMPTION

............................................ 157

F IGURE 9. W ELLS IN L INCOLN P ARK USED TO IRRIGATE FRUIT AND VEGETABLE GARDENS

.......................................................... 158

F IGURE 10. W ELLS IN L INCOLN P ARK USED TO WATER LIVESTOCK

........................................................................................ 159

F IGURE 11. W ELLS IN L INCOLN P ARK USED TO WATER LAWNS

............................................................................................ 160

F IGURE 12. M OLYBDENUM CONCENTRATIONS IN W ELL 138

.............................................................................................. 161Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment

F IGURE 13. S ELENIUM CONCENTRATIONS IN W ELL 138

.................................................................................................... 162

F IGURE 14. D ISSOLVED URANIUM CONCENTRATIONS IN W ELL 138

..................................................................................... 163

F IGURE 15. M OLYBDENUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED

........................................................ 164

F IGURE 16. S ELENIUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED

............................................................... 165

F IGURE 17. D ISSOLVED URANIUM CONCENTRATIONS IN ALL GROUNDWATER WELLS EVALUATED

................................................ 166

F IGURE 18. S AMPLING ZONES ESTABLISHED DURING THE 1998 S UPPLEMENTAL H UMAN H EALTH R ISK A SSESSMENT

.................... 167

F IGURE 19. L OCATIONS OF SOIL SAMPLES TAKEN ALONG THE COUNTY ROAD AND C OTTER M ILL ’ S ACCESS ROAD

........................... 168

F IGURE 20. L OCATIONS OF SOIL SAMPLES TAKEN BY CDPHE IN J ANUARY 2003

..................................................................... 169

F IGURE 21. L OCATION OF AIR SAMPLING LOCATIONS WHERE SOIL SAMPLES ARE COLLECTED

...................................................... 170

F IGURE 22. S AND C REEK C LEANUP P ROJECT

................................................................................................................... 171

F IGURE 23. A PPROXIMATE L OCATIONS OF C OTTER M ILL M ONITORING S TATIONS

.................................................................. 172

APPENDIX C

‐ ATSDR'S EVALUATION PROCESS AND EXPOSURE DOSE CALCULATIONS

T ABLE C1. S UMMARY OF E XPOSURE F ACTORS AND E XPOSURE D OSES FOR THE D RINKING W ATER P ATHWAY FOR C HEMICALS AT THE

C OTTER M ILL S ITE

...................................................................................................................................................... 176

T ABLE C2. S UMMARY OF E XPOSURE F ACTORS AND E XPOSURE D OSES FOR THE S OIL E XPOSURE P ATHWAY FOR C HEMICALS AT THE

T ABLE C3. S UMMARY OF E XPOSURE F ACTORS AND E XPOSURE D OSES FOR THE S URFACE W ATER P ATHWAY FOR C HEMICALS AT THE C OTTER M ILL S ITE

...................................................................................................................................................... 179

C OTTER M ILL S ITE

...................................................................................................................................................... 182

T ABLE C4. S UMMARY OF E XPOSURE D OSES FOR L OCAL F RUITS AND V EGETABLES I RRIGATED WITH C ONTAMINATED W ELL W ATER

.. 184

APPENDIX D. ATSDR GLOSSARY OF ENVIRONMENTAL HEALTH TERMS

............................................................. 189

### CV Public Health Assessment, Lincoln Park/Cotter Uranium Mill Supe rfund Site, Public Comment



## Acronyms and Abbeviations

CCAT Colorado Citizens Against Toxic Waste

CDPHE Colorado Department of Public Health and Environment

CREG cancer risk evaluation guide

comparison value

D dissolved

EMEG environmental media evaluation guide

EPA US Environmental Protection Agency

LPWUS Lincoln Park Water Use Survey

LTHA lifetime health advisory for drinking water

MCL maximum contaminant level

mg/L milligrams per liter

μR/hr microroentgen per hour

N not defined in the CDPHE database

NA not available

ND not detected

NPL National Priorities List

OU operable units

pCi/g picocuries per gram

pCi/L picocuries per liter

ppm parts per million

RAP Remedial Action Plan

RBC risk based concentration

RMEG reference dose media evaluation guide

S suspended

SCS Soil Conservation Service

SSL soil screening level

T total

UMTRCA 1978 Uranium Mill Tailings Radiation Control Act

USGS United States Geological Survey

### ____________________________________________________________

____________________________________________________________

____________________________________________________________ Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## I. SUMMARY

Introduction ATSDR’s top priority is to ensure that the community of Lincoln Park and

surrounding communities have the best information possible to safeguard

their health.

The purpose of this public health assessment (PHA) is to evaluate

available data and information on th e release of hazardous substances

from the Cotter Uranium Mill to determine if people could be harmed by

coming into contact with those substances. This PHA will also list actions,

as needed, to be taken to protect the public’s health.

Background

The Cotter Uranium Mill (Cotter) is located approximately two miles

south of downtown Cañon City in Fremont County, Colorado. The

community of Lincoln Park borders th e site to the north and the housing

developments of Dawson Ranch, Wo lf Park, and Eagle Heights are

located along Cotter’s western boundar y. The nearest residence is about

0.25 miles from the mill (Galant et al. 2007).

The 2,500-acre site includes two in active mills, ore stockpile areas, a

partially reclaimed tailings pond disposal area (i.e., the old ponds area),

and a current tailings pond disposal area (i.e., the lined “main

impoundment area”). A large portion of the site is used to store waste

products in the impoundment area. The fo rmer mill area is fenced and is

known as the “restricted area”.

The Cotter Mill began operations in 1958, extracting uranium ore using an

alkaline leach process. In 1979, the f acility switched to an acid leach

process for extracting uranium. Cotte r suspended primary operations in

1987, and only limited and intermittent processing occurred until the

facility resumed operations in 1999 with a modified alkaline-leaching

capability until 2001. Cotter refabricat ed the mill circuits between 2002

and 2005 to operate using an acid proce ss when it went into stand down in

March 2006. Cotter is currently evaluating whether to re-engineer the mill

for future operation.

Wastes containing metals and radionuc lides were released from Cotter and

entered the nearby environment. Peopl e could potentially be exposed to

these wastes if they come into contact with them in drinking water, soil,

sediment, biota (fruits and vege tables) or ambient air.

Conclusions After evaluati ng the available data, ATSDR reached four important

conclusions in this public health assessment:

1

### ____________________________________________________________

____________________________________________________________

____________________________________________________________

___________________________________________________________ ____________________________________________________________ Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Conclusion 1 ATSDR concludes that drinking water from contaminated private wells

could harm people’s health. This is a public health hazard.

Basis for Conclusion Private well sampling da ta collected from 1984 to 2007 revealed the

presence of molybdenum at levels that could harm people’s health. A

water use survey conducted in Lincoln Pa rk in 1989 revealed that at least

seven people used groundwater (from their private wells) for personal

consumption. These and other residents whose private wells were affected

by the highest molybdenum contaminati on may be at increased risk for

health effects such as gout-like cond itions. Individuals who do not take in

enough dietary copper or who cannot proces s it correctly will be affected

the most.

The lack of consistent monitoring over the years a nd the unknown usage

of wells before the inst allation of the public water supply makes these past

exposures difficult to accurately assess.

Most town residents are now connect ed to the public water supply and

have thus eliminated their exposure to contaminated water. However,

some residents are reported to have refused public water supply

connections, and many may still have operational private wells.

Additionally, no formal institutional c ontrols exist to control groundwater

use in Lincoln Park. Therefore, current and future uses of private wells for

domestic purposes are still possible.

Conclusion 2 ATSDR concludes that accidentally eating or touching soil and sediment

near the Cotter Mill property or in Lincoln Park will not harm people’s

health. However, ATSDR cannot make conclusions about whether lead in

soils near Cotter Mill could harm people’s health in the future.

Basis for Conclusion Currently, the property near the Cotter Mill property is restricted access,

vacant or used for industrial purposes; therefore, contact with soils near

the property should be minimal. The soil sampling conducted at the site

does not allow ATSDR to accurately asse ss potential exposures if the area

is ever developed for residential, commercial or recreational uses.

Therefore, a conclusion regarding future exposures cannot be made

because not enough information is available about future development of

this area.

ATSDR recommends that lead contamination in soil be re-evaluated if

2

### ____________________________________________________________ ____________________________________________________________

____________________________________________________________ Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Next Steps the area is considered for de velopment for residential or non-industrial

uses.

____________________________________________________________

Conclusion 3 ATSDR concludes that eating locally-grown frui ts and vegetables irrigated

with private well water will not harm most people’s health. However, a

person eating above-average amounts of fr uits and vegetables (4 times the

average consumer) might have a low increased risk for developing cancer

over a lifetime. As a precaution, residents should limit their use of

contaminated well water to irrigate their crops. In all cases, the crops

should be thoroughly clea ned prior to eating.

____________________________________________________________

Basis for Conclusion Sampled locally-grown fruits and vegetables did not indicate the presence

of contaminants at levels that woul d cause non-cancer health effects. The

increased cancer risk is based on a person consuming more fruits and

vegetables (95th percentile range) than a typical consumer. The cancer

estimate is conservative because it as sumes that a person would grow and

eat fruits and vegetables that contai n arsenic every day for 30 years. The

amount of fruits and vegetables ea ten will likely be much less than

estimated, mainly because the gr owing season is not year-round.

The amount of a contaminant ingest ed would depend upon the type of

crop eaten, the likelihood of the crop bioaccumulating any of the

contaminants, how often the crop is ea ten, if contaminated well water is

used to irrigate the crop, and if th e crop is thoroughly cleaned prior to

eating them.

Conclusion 4 ATSDR concludes that ambi ent air emissions of particle bound

radionuclides have not resulted in expo sures to the public at levels that

could cause adverse health outcomes.

Basis for Conclusion With the exception of thorium-230 levels observed in 1981 and 1982,

associated with excavation of contam inated tailings, every radionuclide

monitored has been more than a factor of ten below annual dose based

health limits to the public. The excav ation releases appear to have only

exposed on-site workers, but still below occupational limits at that time.

ATSDR is taking the following follow-up actions at this site:

Next Steps ATSDR’s Health Promoti on and Community Involvement Branch

(HPCIB) will conduct health-related educational activities in the

community, as necessary.

3

### ____________________________________________________________ Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### ATSDR’s HPCIB will coordinate community outreach and community

involvement activities for the site.

ATSDR will continue to work with appropriate state and federal agencies

and review additional relevant environmental data (including the water use

survey) as it becomes available.

ATSDR will update the action plan for this site as needed. New

environmental, toxicological, health outcome data, or implementing the

above proposed actions may necessitate the need for additional or

alternative actions at this site.

For More If you have concerns about your health, you should contact you health

Information care provider. You can also call ATSDR at 1-800-CDC-INFO for more

information on the Lincoln Park/Cotter Uranium Mill site.

4Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## II. BACKGROUND

A. Site description and operational history

The Cotter Mill is located appr oximately two miles south of downtown Cañon City in Fremont

County, Colorado (see Figure 1) [Galant et al. 2007]. The commun ity of Lincoln Park borders

the site to the north and the housing developm ents of Dawson Ranch, Wolf Park, and Eagle

Heights are located along Cotter’s western boundar y. The nearest residence is about 0.25 miles

from the mill [Galant et al. 2007].

The 2,500-acre site includes two in active mills, ore stockpile areas, a partially reclaimed tailings

pond disposal area (i.e., the old pond s area), and a current taili ngs pond disposal area (i.e., the

lined “main impoundment area”). A la rge portion of the site is used to store waste products in the

impoundment area. The former mill area is fenced and is known as the “restricted area” [Galant

et al. 2007].

The Cotter Mill began operations in 1958, extr acting uranium ore usi ng an alkaline leach

process. In 1979, the facility switched to an ac id leach process for extracting uranium. Cotter

suspended primary operations in 1987 [Weston 1998], and only limited and intermittent

processing occurred until the facility resumed operations in 1999 with a modified alkalineleaching capability until 2001 [EPA 2002]. Cotter refabricated th e mill circuits between 2002

and 2005 to operate using an acid process when it went into stand down in March 2006 [Cotter

2007]. Cotter is currently evaluating whether to re-engineer the mill for future operation

[CDPHE 2008].

Additional information about the history and lic ensing of the Cotter Mill can be found on the

Colorado Department of Public Health and E nvironment’s (CDPHE) and the US Environmental

Protection Agency’s (EPA) Web sites at http://www.cdphe.state.co.us/h m/cotter/sitedescript.htm

and http://www.epa.gov/region8/superfund/co/lincolnpark/

.

B. Remedial and regulatory history

Originally, mill tailings (i.e., solid ore processi ng waste), raffinate (liquid waste that remains

after extraction), and other liquids from the alkali ne leach process were stored in ten on-site

unlined ponds. In 1978, lined impoundments were built on site to store process waste products.

The main impoundment contained two cells to segr egate acid-leach tailings and liquids in the

primary impoundment cell from alkaline-leach ta ilings in the secondary impoundment cell (EPA

2002). By 1983, more than 2.5 million cubic yards of waste products from historic operations

were transferred from the original unlined ponds to the secondary impoundment. All new process

wastes are stored in the lined prim ary impoundment [Galant et al. 2007].

Because Cotter Mill operations released radionu clides and metals into the environment, soil

around the mill and groundwater in the nearby Linc oln Park community became contaminated,

primarily with molybdenum and uranium [CDPHE

2008]. In 1984, the Lincoln Park/Cotter Mill Site was

added to the Superfund National Priorities List (NPL)

[EPA 2008]. EPA divided the site into two operable According to a signed Memorandum

of Understanding, CDPHE is the lead

regulatory agency overseeing

cleanup at the Cotter Mill.

5Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### units (OUs)—OU1 consists of the on-site contamination and OU2 is the neighborhood of

Lincoln Park (i.e., the off-site impacted ar ea) [CDPHE 2008; EPA 2007]. Together, the Lincoln

Park/Cotter Mill Superfund Site encompasses ab out 7.8 square miles (5,000 acres) [EPA 2004].

In 1988, the Cotter Corporation and CDPHE signed a Consent Decree and Remedial Action Plan

(RAP) [Galant et al. 2007]. The purpose of the court-ordered action was to assess and mitigate

human and environmental impacts from the Cotter Mill. As part of the settlement, Cotter agreed

to clean up the site at the cor poration’s expense [EPA 2008]. The cleanup was estimated to take

16 years and cost $11 million [Galant et al. 2007]. EPA and the US Department of Energy have

also contributed to cleanup costs [DOE 2003]. Re medial activities have focused on eliminating

the sources of contamination at the Cotter Mill and eliminati ng exposures to Lincoln Park

residents [CDPHE 2008]. Many of the activities outlined in the 1988 RAP have been completed,

including the following:

 Connecting Lincoln Park re sidents to city water;

 Constructing a groundwater barrier at the So il Conservation Service (SCS) Flood Control

Dam to minimize migration of contamin ated groundwater into Lincoln Park;

 Moving tailings and contaminated soils into a lined impoundment to eliminate them as a

source of contamination; and

 Excavating contaminated stream sediments in Sand Creek.

The old ponds area was undergoing reclamation in late 2008 [Pat Smith, EPA Region 8, personal

communication, August 2008]. Remain ing activities include groundwat er remediation and final

site cleanup [CDPHE 2008; Gala nt et al. 2007]. Groundwater reme diation activities have shown

some positive results. However, the balance of the remedial activities listed in the Consent

Decree have not been successful enough in m itigating the plume, and most have been

discontinued (e.g., barrier wall, dam to ditch flushing, calcium-polysul fide fix/flush, and

permeable reactive treatment wall). Table 1 below lists a timeline of process events, remedial

activities, and government actions for the Lincoln Park/Cotter Mill Superfund Site.

6Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 1. Lincoln Park/Cotter Mill Superfund Site Activity Timeline

Date Type of

Event 1 

### Event 2



### July 1958 Process Cotter Corporation began alkali leach process operations (licensing by the Atomic

Energy Commission)

June 1965 Event Flood that caused the unlined taili ngs ponds at the Cotter Mill to overflow into

Lincoln Park

1971 Remediation SCS Dam completed; dam pumps impounded surface water back to the main

impoundment (groundwater barrier completed at a later date after 1988 RAP)

July 1972 Remediation Pond 2 lined

June 1976 Remediation Pond 10 lined

1978–1979 Remediation A new lined impoundment consisting of two cells (primary and secondary)

constructed adjacent to the old ponds area for management of wastes from the

new mill (alkali process)

1979 Remediation The old mill was demolished and new mill construction began

1979–

present Remediation Impounded water at the SCS Dam pumped back to the main impoundment

1979–1998 Process Operations switched from an alkali leach process to an acid leach mill; continuing

operations intermittently

1980 Remediation Old upstream method tailings ponds replaced by a full-height compacted earth

embankment

1980 Remediation Construction of Well 333 just north of Cotter; well removes contaminated water

flowing from the old ponds area

June 1981 Remediation Pond 3 lined

1981–1983 Remediation Tailings from the unlined old ponds area (~2.5 million cubic yards) removed and

placed in the new impoundment

December

9, 1983 Government

Action State of Colorado files a complaint against Cotter under the Comprehensive

Environmental Response, Compensation, and Liability Act of 1980 (CERCLA)

September

21, 1984 Government

Action Cotter (OU1) and Lincoln Park (OU2) added to the NPL

1985–1986 Investigation Remedial Investigat ion and Feasibility Study (GeoTrans 1986)

April 1986 Government

Action Memorandum of Agreement between EPA and the state of Colorado

April 8, 1988 Government

Action Consent decree signed, including a RAP that required cleanup activities

1988 Remediation An additional 2 feet of soil was removed from the old ponds area and placed in the

lined primary impoundment

1988 Remediation Lined water distribution/surge pond constructed over Pond 7

1988 Remediation Installation of a hydrologic clay barrier upgradient from the SCS Dam

1989 Remediation The secondary impoundment cell was covered with liquid for dust control and to

create evaporative capacity; additional contaminated soils were removed from the

old ponds area and placed in the primary impoundment cell

7Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Date Type of

Event 1 

### Event 2



### 1989–2000 Remediation Installation of two hydraulic barriers (injection/withdrawal systems) to control

groundwater flow from the old ponds area; discontinued in 2000 because the

system was unproductive

1990–1996 Remediation SCS Dam to DeWeese ditch flushing project

1990–1998 Remediation Four pilot tests to evaluate the effectiveness of active flushing of vadose zone and

aquifer for contaminant removal in OU1

October 29,

1991 Report Health Risk Assessment of the Cotter Uranium Mill Site: Phase I (HRAP 1991)

January 7,

1993 Report RAP final report, Willow Lakes (Cotter)

1993–1999 Remediation Sand Creek Soil Cleanup Action identified and removed approximately 9,000 cubic

yards of tailings, soil, and sediment from Sand Creek (Cotter 2000)

1995 Licensing Cotter filed a license amendment with the state for alkaline leach processing of

uranium ore (approved 2/97)

November

19, 1996 Report Supplemental Human Health Risk Assessment: Phase II Final Report (Weston

1996)

1996–1998 Remediation Flush/fixation process using Calcium Polysulfide in surface infiltration cells

February

1997 Government

Action Radioactive materials license amendment became effective

1998 Process Mill reconverted to an alkaline leach process

September

29, 1998 Report Ecological Risk Assessment, Lincoln Park Superfund Site (Stoller Corporation and

Schafer & Associates)

1998 Report Supplemental Hu man Health Risk Assessment, Ph ase III Final Report (Weston

1998)

1999 Remediation Old ponds area surface soils (~100,000 cubic yards) were removed and placed in

the lined primary impoundment

May 1999 Process Cotter resumed operations (which had been intermittent since 1979) with modified

alkaline-leaching capability

September

30, 1999 Investigation Final Focused F easibility Study, Lincoln Park

June 2000 Remediation Installation of a permeable reactive treatment wall across Sand Creek channel,

north of SCS Dam in DeWeese Dye Ditch flush (to fulfill EPA requirement to

address contaminated groundwater that was bypassing the SCS Dam barrier)

2000–2005 Process Cotter proposes modifications to the circuit to process zircon ore. Process was not

successful and discontinued by 2005.

January

2002 Government

Action EPA issued a Record of Decision for Lincol n Park requiring “No Further Action” for

surface soils within Li ncoln Park (EPA 2002)

April 2002 Government

Action The governor of Colorado passed an emergency bill requiring an Environmental

Assessment be conducted before shipping out-of-state radioactive waste to Cotter

July 9, 2002 Government

Action CDPHE denied Cotter’s license amendment request, preventing receipt of

shipments for direct disposal

8Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Date Type of

Event 1 

### Event 2



### September

13, 2002 Government

Action State of Colorado allowed Cotter to receive limited amounts of waste material as a

test of its handling /storage capability

2002/2003 Investigation Sampling for plutonium, uranium, lead and molybdenum in the Canon City vicinity

(CDPHE 2003)

January 3,

2003 Government

Action EPA issued a notice of unacceptability under the Off-Site Rule regarding the five

Proposed Units and impoundments previously found acceptable

2003 Remediation Permeable reactive treatment wall not functioning as designed

September

9, 2004 Investigation Cotter submits Feasibility Study for Old Ponds Area with six alternatives

December

15, 2004 Government

Action State health officials approved a 5-year ex tension of Cotter’s uranium-processing

license but denied requests to become a disposal facility for off-site radioactive

materials

February 1,

2005 Government

Action Cotter filed a request for a hearing regarding the conditions of the license renewal

October

2005 Investigation Survey of lead in indoor dust, soils, and blood in Lincoln Park to investigate

potential impacts of historic smelters (ATSDR 2006a, 2006b, 2006c, 2006d)

April 2006 Government

Action A judge recommended in CDPHE’s favor and Cotter filed an exception on the direct

disposal issue only

2006 Remediation To replace the permeable reactive treatment wall, water building up behind barrier

is pumped back to the impoundments

January

2007 Government

Action CDPHE signed a Final Agency Decision, affirming the judge’s Decision on the

license. Cotter filed an appeal to be able to dispose of out-of-state soils in its

primary impoundment.

2008 Process Cotter decides not to take the case to the Court of Appeals, effectively ending the

licensing issues from the 2004 renewal.

1 Describes the general nature of events/actions re lating to the Lincoln Park/Cotter Mill Superfund Site.

2 Includes events/actions most pertinent to ATSDR’s evalua tion of exposures and potential health effects. Not all

site-related events and reports are included.

9Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### C. Demographics

ATSDR examines demographic data to identif y sensitive populations, such as young children,

the elderly, and women of childbearing age, and to determine whether these sensitive

populations are exposed to any pot ential health risks. Demogra phics also provide details on

population mobility and residential history in a pa rticular area. This information helps ATSDR

evaluate how long residents might have been exposed to contaminants. According to the 2000

census, 1,170 people live within one mile of the Cotter Mill pr operty—90 of whom are age 6 or

younger, 190 are women of childbearing age (15–44 years), and 243 ar e age 65 or older. Figure 2

in Appendix B shows the demographics within one mile of the mill.

Cañon City is the largest population center in Fremont County with 15,760 residents (see Table 2

below). The Cañon City Metro area includes Cañ on City, North Cañon, Lincoln Park, Brookside,

Prospect Heights, Four Mile Ranch, Shadow Hills, Dawson Ranch, and the Colorado State

Correctional Facilities. Florence is the second la rgest community in the ar ea with a population of

3,816. The unincorporated portions of Fremont County represent 55% of the population and

include Lincoln Park, Prospect Height s, and Shadow Hills [Cotter 2007].

Table 2. Population of communities near the Cotter Mill

Community 2000 Census Population 2006 Population Estimate

Brookside 219 218

Cañon City 15,431 15,760

Coal Creek 303 380

Florence 3,653 3,816

Lincoln Park 3,904 Not available

Rockvale 426 432

Williamsburg 714 700

Fremont County 46,145 47,727

Source: Cotter 2007; Galant et al. 2007



### The unincorporated community of Lincoln Park is located in th e greater Cañon City area, south

of the Arkansas River and north of the Cotter Mill (see Figure 1). The community consists of

single and multi-family homes, trailer parks, and rural single family homes. Many of the

residents are retired and own their homes. Th e Lincoln Park area is currently experiencing

growth [Galant et al. 2007].

The largest employers in Fremont County are th e Colorado Department of Corrections and the

Federal Bureau of Prisons. Tourism is the seco nd largest employer in the Cañon City area [Cotter

2007; Galant et al. 2007]. Additional industry an d manufacturing employers in Fremont County

include Portec, Inc.; Holcim, Inc.; Thermal Ceramics; and Cañon Industrial Ceramics [Cotter

2007]. The health care and school systems also employ a substantial number of people in the

county [CCAT, personal communication, August 2008].

10Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### D. Land use and natural resources

The Cotter Mill is located within an industrial zone. All abutting lands are zoned for agricultureforestry. The semi-rural community of Lincoln Pa rk is comprised predominantly of residential

developments, agricultural plots and orchards, an d small grazing parcels. The Shadow Hills Golf

Course is located to the north of the Cotter Mill complex. The land to the south and east of the

site is largely undeveloped. Recently, several hi gh end homes have been built near the golf

course and in the Wolf Park and Dawson Ranch ar eas. The distance from Cotter Mill’s restricted

area to the nearest home is about 0.25 mile [Galan t et al. 2007].

Fremont County contains a large amount of public land managed by the US Department of the

Interior Bureau of Land Management and the US Department of Agriculture Forest Service.

Some of these areas are leased for livestock grazing, aggregate mining, and firewood removal.

Visiting the many scenic attractions in Colora do’s High Country (e.g., the Royal Gorge Bridge)

and rafting in the Arkansas River are popul ar recreational acti vities [Cotter 2007].

1. Hydrogeology

In the vicinity of the Cotter Mill, contaminat ed groundwater primarily migrates along the near

surface alluvium and fractured, weathered bedr ock immediately underlying the alluvium (<100

feet deep) [USGS 1999a]. Groundwater migration is generally in northerly directions from the

mill area, along the Sand Creek drainage area, th rough a gap in Raton Ridge, and into Lincoln

Park. However, groundwater contamination has also been found in the vicinity of the Shadow

Hills Golf Course, which is west of the Sa nd Creek drainage [EPA 2007]. The hydrogeology of

the Lincoln Park/Cotter Mill Supe rfund Site can be conceptually divided into two areas: the

upgradient area near the mill and the downgradient area to the north-northeast in Lincoln Park

[USGS 1999a].

 In the upgradient area near the mill, the ra te of groundwater flow is limited by small

hydraulic conductivities [USGS 199 9a]. However, cracks in the bedrock, fractures, and

weathering enhance water transmission and allo w groundwater to travel at considerable

rates. Monitoring wells in the upgradient area, specifically in the Poison Canyon

Formation, yield small amounts of water.

 The downgradient area in Lincoln Park is characterized by an “alluvial aquifer”

comprised of alluvium and terrace alluvium, to a depth of 0–60 feet, and the underlying

weathered and/or fractured bedr ock below the alluvium. In this area, groundwater can be

transmitted at substantial rates. The mix of gravel, sand, silt, and clay in this aquifer

yields 10 to 400 gallons per minute to wells in Lincoln Park. The aquifer discharges to

Sand Creek, as well as to multiple springs and seeps as far downgradient as the Arkansas

River, approximately 2.5 miles dow ngradient from the Cotter site.

2. Geology

The Cotter Mill is located in a topographic de pression resulting from an underlying structure

called the Chandler syncline. The core of the syncline is the Poison Canyon formation, which is

the uppermost bedrock unit beneath the site. Soils near the mill are shallow and well drained.

11Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### The top layer consists of brown loam. The subsoil is a pale brown loam, grading into a yellowish

brown sandy loam. Areas north of the mill are cove red with Quaternary alluvium consisting of

gravel, cobble, boulders, and sand [EPA 2002].

3. Hydrology

The Cotter Mill lies within the Sand Creek watershed [HRAP 1991]. The main hydrologic

feature of the Lincoln Pa rk/Cotter Mill Superfund

Site is Sand Creek, a primarily ephemeral creek [EPA

2007]. The creek originates at Dawson Mountain An ephemeral creek has flowing water

only during, and for a short duration

after, precipitation. A perennial creek 

### (south of the Cotter Mill), travels north through the has flowing water year-round.



### Cotter Mill, intersects the DeWeese Dye Ditch, and

runs north-northeast through Lincoln Park. It becomes perennial for the last 0.25–0.5 mile before

its confluence with the Arkansas River. The DeWeese Dye Ditch is one irrigation ditch that

flows between the Cotter Mill and Lincoln Park.

Alluvial material (sediment deposited by flowing water) associ ated with Sand Creek is the

predominant migration pathway for mill-derive d contaminants in groundwater. Sand Creek

carved a channel into the Vermejo formation at the Raton outcrop in the vicinity of the SCS

Dam, which filled with permeable sediments, creating a preferential pathway for alluvial

groundwater into Lincoln Park. The alluvial aquife r in Lincoln Park receives recharge from the

DeWeese Dye Ditch, Crooked Ditch, Pump Ditc h, ditch laterals, and ponds filled by the

DeWeese Dye Ditch [EPA 2007].

4. Prevailing Wind Patterns

Cotter’s monitoring network includes an on-site meteorological stat ion that continuously

measures a standard set of meteorological parameters (e.g., wind speed, wind direction,

temperature, and relative humidity). The wind rose in Figure 3 in Appendix B depicts the

statistical distribution of m easured wind speeds and wind directions. During 2008, wind patterns

at the station were principally westerly (i.e ., winds out of the sout hwest to northwest) and

accounted for 55% of the total winds [Cotter 2008b]. Easterly winds (i.e., winds out of the

southeast to northeast) accounted for a smaller, but still signi ficant, portion (26%) of the

observed wind directions. Southerly and norther ly winds were much less common. A nearly

identical profile was observed in 2007. Other av erage parameters measured in 2008 follow: air

temperature of 53.4 °F; relative humidity of 41%; and rainfall of 5.18 inches.

The prevailing westerly and easterl y wind patterns are reas onably consistent w ith trends in the

observed concentrations. Ambient air concentrati ons of selected site-r elated pollutants were

highest at the perimeter monitori ng stations directly east and west of the primary operations.

There is a hilly ridge that straddles the wester n border of the site, blocking much east/west wind

flow. However, it should be noted that prevaili ng wind patterns measured at Cotter Mill may not

be representative of surface winds throughout the area, especially considering the proximity of

nearby terrain features.

12Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### E. Past ATSDR involvement

ATSDR has been involved with the Lincoln Pa rk site in the past. In October 1983, ATSDR

completed a Public Health Assessment for the site. After reviewing available groundwater data,

ATSDR concluded that the poten tial long term health effects from consumption of the

contaminated water were:

 cancer and kidney damage, from uranium;

 gout-like symptoms, from molybdenum; and

 possibly a group of physiological and psyc hological symptoms, from selenium.

None of the potential health effects were definitive.

Numerous questions and concerns have been voiced by residents of Lincoln Park regarding the

historical sites of numerous milling and sme lting facilities in the Ca ñon City area. Among the

various concerns were specific concerns about residual lead contamination from these milling

and smelting operations. In response to these con cerns, and after a specific request by the EPA,

ATSDR evaluated the health risks associated with lead contamination in the area. ATSDR

focused on two primary issues: 1) the blood lead level of children living in the area and 2) lead

contaminated dust in homes in the Lincoln Park area.

In September and October 2005, ATSDR conducted an Exposure Investiga tion (EI) to answer

the questions presented by the community and EPA. Previousl y, ATSDR concluded that lead

levels in house dust and lead exposures to child ren represented an indeterminate health hazard

because of a lack of available data. ATSDR conduc ted the EI to gather data on blood lead levels

in the children, and soil and i ndoor dust level from homes.

The activities of the EI included:

 Collecting 44 indoor dust samples from 21 homes in Lincoln Park

 Collecting 80 composite soil samples from 22 properties (sampling conducted by EPA)

 Obtaining 45 blood samples from 21 house holds (42 blood sample s were analyzed)

After evaluating the data obtaine d during the EI, ATSDR conclude d that blood lead levels in

adults and children, lead levels in dust in homes, and lead levels in soil did not represent a public

health harard. ATSDR recommended no further actio ns related to lead in dust in homes, but did

recommend routine monitoring of children’s bloo d lead levels in the Lincoln Park area.

In September 2005, ATSDR conducted a blood lead testing program as a service to the

community of Lincoln Park. A total of 115 child ren from a local school were tested for blood

lead. None of the children tested had elevated blood lead leve ls. Therefore, ATSDR concluded

that the children tested did not have unusual ex posures to lead at the time of testing. ATSDR

recommended that local and state agencies conti nue routine monitoring of lead levels in area

children.

13Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Full reports discussed above may be obtained by contacting any of the contacts listed at the end

of this report, by visiting our website at www.atsdr.cdc.gov or by calling our toll-free hotline at

800-232-4636.

14Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## III. EVALUATION OF EX POSURE PATHWAYS

A. What is meant by exposure?

ATSDR’s public health assessments are driven

by exposure to, or contact with, environmental

contaminants. Contaminants released into the

environment have the potential to cause

harmful health effects. Nevertheless, a release

does not always result in exposure. People can

only be exposed to a contaminant if they come

in contact with that contaminant—if they

breathe, eat, drink, or come into skin contact

with a substance containing the contaminant. If

no one comes in contact with a contaminant,

then no exposure occurs, and thus no health

effects could occur. Often the general public

does not have access to the source area of An exposure pathway has five elements: (1) a

source of contamination, (2) an environmental

media, (3) a point of exposure, (4) a route of

human exposure, and (5) a receptor

population. The source is the place where the

chemical or radioactive material was released.

The environmental media (such as

groundwater, soil, surface water, or air)

transport the contaminants. The point of

exposure is the place where people come into

contact with the contaminated media. The

route of exposure (for example, ingestion,

inhalation, or dermal contact) is the way the

contaminant enters the body. The people

actually exposed are the receptor population

.



### contamination or areas where contaminants are moving through the environment. This lack of

access to these areas becomes important in dete rmining whether people could come in contact

with the contaminants.

The route of a contaminant’s movement is the pathway . ATSDR identifies and evaluates

exposure pathways by considering how people might come in contact with a contaminant. An

exposure pathway could involve air, surface water, groundwater, soil, dust, or even plants and

animals. Exposure can occur by breathing, eating, drinking, or by skin contact with a substance

containing the chemical contaminant. ATSDR id entifies an exposure pathway as completed or

potential, or eliminates the pa thway from further evaluation.

 Completed exposure pathways exist for a past, current, or future exposure if contaminant

sources can be linked to a receptor population. All five elements of the exposure pathway

must be present. In other words, people have or are likely to come in contact with siterelated contamination at a part icular exposure point via an id entified exposure route. As

stated above, a release of a chemical or ra dioactive materi al into the environment does

not always result in human exposure. For an exposure to occur, a completed exposure

pathway must exist.

 Potential exposure pathways indicate that exposure to a contaminant could have occurred

in the past, could be occurring currently, or could occur in the future. It exists when one

or more of the elements are missing but av ailable information indicates possible human

exposure. A potential exposure pathway is one which ATSDR cannot rule out, even

though not all of the five elements are identifiable.

 An eliminated exposure pathway exists when one or more of the elements are missing.

Exposure pathways can be ruled out if the site characteristics make past, current, and

future human exposures extremely unlikely. If people do not have access to contaminated

15Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### areas, the pathway is eliminated from furt her evaluation. Also, an exposure pathway is

eliminated if site monitoring reveals that media in accessible areas are not contaminated.

Contact with contamination at the Cotter Mill is an eliminated exposure pathway.

Because the mill site itself is fenc ed and access is restricted, exposure to on-site contamination by the

public at the Cotter Mill is limited. Further, remedi ation efforts have removed some of the on-site soil

contamination, including moving millions of cubic ya rds of tailings and contaminated soils from unlined

ponds to lined impoundments (EPA 2002). In some areas, contaminated soil was removed down to

bedrock. In addition, various proc ess changes reduced t he release of contaminated materials (EPA

2002). Any potential exposure by the occasional tres passer to remaining impacted soils at the Cotter

Mill would be too infrequent to present a health hazard.



### B. How does ATSDR determine which exposure situations to evaluate?

ATSDR scientists evaluate site conditions to dete rmine if people could ha ve been, are, or could

be exposed (i.e., exposed in a past scenario, a cu rrent scenario, or a futu re scenario) to siterelated contaminants. When evaluating exposur e pathways, ATSDR identifies whether exposure

to contaminated media (soil, sediment, water, ai r, or biota) has occurr ed, is occurring, or will

occur through ingestion, dermal (s kin) contact, or inhalation.

If exposure was, is, or could be possible, ATSD R scientists consider wh ether contamination is

present at levels that might aff ect public health. ATSDR scientists select contaminants for further

evaluation by comparing them to health-bas ed comparison values. These are developed by

ATSDR from available scientific literature related to exposure and health effects. Comparison

values are derived for each of the different media and reflect an estimated contaminant

concentration that is not likely to cause adverse health effects for a given chemical, assuming a

standard daily contact rate (e .g., an amount of water or soil consumed or an amount of air

breathed) and body weight.

Comparison values are not threshol ds for adverse health effects . ATSDR comparison values

establish contaminant concentrations many times lower than levels at which no effects were

observed in experimental animals or human epidemiologic studies. If contaminant concentrations

are above comparison values, ATSDR further analyzes exposure vari ables (for example, duration

and frequency of exposure), the toxicology of th e contaminant, other epidemiology studies, and

the weight of evidence for health effects.

Some of the comparison values used by ATSD R scientists include ATSDR’s environmental

media evaluation guides (EMEGs), reference dose media evaluation guides (RMEGs), and

cancer risk evaluation guides (CREGs) and EPA’s maximum contaminant levels (MCLs).

EMEGs, RMEGs, and CREGs are non-enforceable, health-based comparison values developed

by ATSDR for screening environmental contamination for further evaluation. MCLs are

enforceable drinking water regulations developed to protect public he alth. Effective May 2008,

Colorado established state groundwater st andards for uranium and molybdenum.

You can find out more about the ATSDR eval uation process by calling ATSDR’s toll-free

telephone number, 1-800-CDC-INFO (1-800-232- 4636) or reading ATSDR’s Public Health

Assessment Guidance Manual at http://www.atsdr.cdc.gov/HAC/PHAManual /

.

16Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### C. If someone is exposed, will they get sick?

Exposure does not always result in harmful health effects . The type and severity of health effects

a person can experience because of contact with a contaminant depend on the exposure

concentration (how much), the frequency (how often) and/or duration of exposure (how long),

the route or pathway of exposure (breathing, eating, drinking, or skin contact), and the

multiplicity of exposure (combination of contamin ants). Once exposure occurs, characteristics

such as age, sex, nutritional status , genetics, lifestyle, and health status of the exposed individual

influence how the individual absorbs, distributes , metabolizes, and excretes the contaminant.

Together, these factors and char acteristics determine the health effects that may occur.

In almost any situation, there is considerable uncertainty about the true level of exposure to

environmental contamination. To account for this uncertainty and to be protective of public

health, ATSDR scientists typically use worst- case exposure level estimates as the basis for

determining whether adverse health effects are possible. These estimated exposure levels usually

are much higher than the levels that people are r eally exposed to. If the exposure levels indicate

that adverse health effects are possible, ATSDR performs more detailed reviews of exposure and

consults the toxicologic and epidemiologic literat ure for scientific information about the health

effects from exposure to hazardous substances.

D. What exposure situations were evaluated for residents living near the Cotter

Mill?

ATSDR obtained information to support the exposure pathway analysis for the Lincoln

Park/Cotter Mill Superfund Site from multiple site investigation repor ts; state, local, and facility

documentation; and communication with local and state officials. The analysis also draws from

available environmental and exposure data for groundwater, soil, surfac e water and sediment,

and biota. Throughout this process, ATSDR exam ined concerns expressed by the community to

ensure exposures of special concern are adequa tely addressed. ATSDR identified the following

exposure pathways for further evaluation:

1. Exposure to site-related contaminants in groundwater in Lincoln Park.

2. Contact with site-related contaminants in soil ad jacent to the Cotter Mill and in Lincoln Park.

3. Contact with site-related contaminants in surface water downstream from the Cotter Mill.

4. Exposure from eating produce locally grown in Lincoln Park.

5. Exposure from site-related soil contaminants in windborne dust.

6. Exposure from air emission sources (stacks and uncontrolled fugitive dust)

This exposure pathway analysis focuses on past , current, and future exposures for residents

living near the Cotter Mill, with a focus on the community of Li ncoln Park. Some attention is

also paid to exposures at the Shadow Hills Go lf Course and along the county road. Table 3 below

provides a summary of exposure pathways eval uated in this public health assessment.

17Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 1. Exposure to groundwater in Lincoln Park

In the past, a number of residences used wells 1 

### on their property (GeoTrans 1986; IMS 1989).

Based on a 1989 water use survey in Lincoln Pa rk, 60 out of 104 wells, springs, and cisterns

were used to obtain water for domestic purposes , including consumption and irrigation (IMS

1989). See Table 14 in Appendix A for the reported groundwater uses in the Lincoln Park area.

Seven survey respondents indicated that they used groundwater for domestic consumption,

accounting for 5 to 100% of their total water consumption. Based on the survey, five residents

had private wells that were affected by cont aminated groundwater; these residents were

connected to the municipal water supply between 1989 and 1993 [EPA 2002]. The 1988 RAP

requires Cotter to connect eligible affected users with legal wate r rights for a we ll to the town

water supply [CDPHE 2005]. Cotte r checks the State of Colorado’ s Engineer’s Office database

for new water permits and reports their findings in their annual ALARA reports [Pat Smith, EPA

Region 8, personal communication, August 2008].

While the majority of town residents are now

connected to the public wa ter supply [Galant et al. The use of private groundwater wells in



### 2007], several residences also have operational

private wells. A 2005 summary of the RAP status

reports that some resident s have refused public water the past was a completed exposure

pathway. Most residences are now

connected to the public water supply.

The current and future use of these 

### supply connections [CDPHE 2005]. Additionally, no wells is a potential exposure pathway



### formal institutional controls exist to control because the extent to which these wells



### groundwater use in Lincoln Park [EPA 2007]. The are used is not well documented.



### United States Geological Surv ey (USGS) reports that

existing private wells are used primarily fo r stock watering and ir rigation [USGS 1999a].

However, a newspaper article reports that at le ast one residence, located on Grand Avenue in

Lincoln Park, used private well water for cons umption as recently as 2002 [Plasket 2002]. Based

on a 2007 review of Colorado State well permits fo r residences in the plume configuration, at

least one well is permitted for irrigation and domestic use, but no details of actual use are

documented [EA 2007]. On properties that contin ue to use private wells, new purchasers are

offered connection to the town’s municipal water system [Galant et al. 2007]. In late 2008, EPA

conducted another water use survey to verify whether groundwater is being utilized by

residences in Lincoln Park. Well water samp les were also collected and analyzed. Once

available, ATSDR will review the information a nd will revise the public health assessment, if

needed.

2. Contact with soil adjacent to the Cotter Mill and in Lincoln Park

People (especially children) might accidentally ingest soil or exposed sediment, and dust

generated from these materials, during normal activities. Everyone ingests some soil or dust

every day. Small children (especially those of pr eschool age) tend to swallow more soil or dust

than any other age group because children of this age tend to have more contact with soil through

play activities and have a tendency for more hand-to-mouth activity. Children in elementary

school, teenagers, and adults swal low much smaller amounts of soil or dust. The amount of grass

1 The term “well” is used to represent all groundw ater sources, and includes both wells and springs.

18Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### cover in an area, the amount of time spent outdoors, and weather conditions also influence how

much contact people have with soil.

a) Contact with soil near the Cotter Mill

Soils adjacent to the Cotter Mill have been contaminated by wind-blow n particulates [CDPHE

2005]. Elevated levels are primarily detected in soils directly east and west of the facility

[Weston 1998]. This distribu tion of contaminated soils

is consistent with wind patte rns in the area, which blow

mainly from west to east with occasional flows from

east to west. The primarily vacant areas directly east

and west of the facility are referred to as a “buffer

zone” between the Cotter Mill and residential

developments [EPA 2002]. Therefore, limited opportunities for exposur e to impacted siteadjacent soils exist—people are not expected to be in this area on a daily basis and for an

extended period of time. One exception may be at the Shadow Hills Golf Course, located

immediately north of the Cotter mill complex. Ex posure to potentially impacted soil at this

public golf course is unli kely due to grass cover. Contact with contaminated soil near

the Cotter Mill (i.e., in the buffer zone)

is a past, current, and future potential

exposure pathway.



### For nearly 50 years, Cotter has intermittently hauled materials by truck, possibly losing some

materials along the county road leading to the f acility and along the access road entering the mill

site [MFG 2005]. The public could be exposed to potentially impacted soils along the county

road. However, there is limited potential for ex posure to contaminants along the access road,

since access to the Cotter Mill is restricted and Cotter remediated soil adjacent to the access road

in 2007 and 2008.

b) Contact with soil and sediment in the community of Lincoln Park

The community of Lincoln Park is located ap proximately 1.5 miles north-northeast of the

restricted area of the Cotter Mill. Contaminated materials from the Cotter Mill may have

contributed to soil contamination in Lincoln Park in two ways:

1. Dust from soil or tailings asso ciated with site operations c ould be transported by wind to

Lincoln Park. However, wind patterns in the area suggest that wi nd-blown contamination

is not likely a considerable source of so il contamination in Lincoln Park (Weston 1998).

Additionally, on-site remediation at the Cotte r Mill substantially re duced the sources of

soil contamination.

2. Potentially impacted groundwater used for ir rigation could lead to the accumulation of

chemicals in town soils [Weston 1998].

Further, in the past, contaminated surface water runoff Contact with contaminated

sediment in Sand Creek was a past 

### from the Cotter Mill entered Sand Creek, where it was

potential exposure pathway. Due to 

### transported downstream toward Lincoln Park [EPA the remediation of Sand Creek, 

### 2002]. However, Sand Creek is not believed to be used current and future contact is an 

### for recreational activities—the creek is ephemeral and on eliminated exposure pathway. 

### private land until it goes under th e river walk and enters

the Arkansas River [Phil Stoffey, CDPH E, personal communication, June 2007].

19Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment

Contact with contaminated soil in Lincoln Park was a past completed exposure pathway. Cotter has

performed all required off-site so il cleanup activities, as outlined in the RAP [EPA 2002]. CDPHE

reports that the Cotter Mill poses no risk to the resi dents of Lincoln Park by exposure to soil [Weston

1998], and EPA and CDPHE have advised “No Further Acti on” in regards to Lincoln Park soils [EPA

2002]. EPA’s Record of Decision states that surface-soil cleanup activi ties have eliminated or reduced

risks to “acceptable” levels [EPA 2002, 2007]. Therefore, current and future contact with soil and

sediment is an eliminated exposure pathway.



### 3. Contact with surface water downstream from the Cotter Mill

In the past, people could have come in contac t with contamination in surface water during

recreational activities. The Arkans as River is used primarily for fishing and boating or rafting, as

well as some swimming [Phil Stoffey, CDPHE,

personal communication, June 2007]. Sand Creek is on Contact with contaminated surface

water near the Cotter Mill was a past 

### private land until it goes under th e river walk and enters

potential exposure pathway. Due to 

### the Arkansas River, and is generally not used for the construction of the SCS Dam and 

### recreational activities [Phil Stoffey, CDPHE, personal the remediation of Sand Creek, 

### communication, June 2007]. Many Lincoln Park current and future contact is an



### residents use water from the DeWeese Dye Ditch to eliminated exposure pathway.



### irrigate their orchards and gardens [Galant et al. 2007].

4. Exposure from eating locally grown produce

Many Lincoln Park residents have orchards and gardens. Water from the DeWeese Dye Ditch is

primarily used to irrigate the orchards and gard ens, however, some residents use water from their

groundwater wells [Galant 2007; IM S 1989]. If fruits and vegetables are grown in contaminated

soil and/or irrigated with contaminated water, the people who eat this pr oduce could be exposed

to contamination.

5. Exposure from breathing windborne dust

Many Lincoln Park residents are concerned about th e arid environment and the risks of breathing

in contaminated dust from the site. The profile of air emission sources at Cotter Mill has changed

considerably over the years. Th ese sources include both releases through stacks and uncontrolled

(or fugitive) dust emissions. Stack emissions occu rred during times of active processing at Cotter

Mill; however, the magnitude of these stack emi ssions has varied, depend ing on production rates

and effectiveness of air pollution controls. The sources of fugitive dust emissions have also

changed. In the past, the site had many uncontro lled sources of wind-blown dust, which would

cause particulate matter (along wi th any chemical and radiological constituents) to be emitted

into the air. Examples of these sources incl ude ore handling operations, stockpiles, and the

previous unlined holding ponds. Many of these sources of wind-blown dust have since been

controlled or eliminated, causing facility-wide fugitive dust emissions to decrease considerably

over the years, though some fugitive dust emissions (e.g., from unpaved roads) continue to

occur.

20Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 3. Exposure pathways for residents living near the Cotter MillExposurePathwayExposure Pathway ElementsTimeFrameCommentsSources ofContaminationFate andTransportPoint ofExposureExposed PopulationRoute ofExposureGroundwaterCompleted Exposure PathwayPrivateTailings and otherMigration ofResidential tapResidents, includingIngestion,PastPast consumption of groundwater fromgroundwaterwastes from thegroundwaterwater drawnchildren, who are notDermalprivate wells has been documentedwellsCotter Mill (heavymetals andradionuclides)into the LincolnPark areafrom privatewellsconnected to the publicwater supply and rely onprivate wellscontactand was, therefore, a completedexposure pathway.Potential Exposure PathwayPrivateTailings and otherMigration ofResidential tapResidents, includingIngestion,CurrentThe extent to which private wells aregroundwaterwastes from thegroundwaterwater drawnchildren, who are notDermalFuturecurrently used in Lincoln Park iswellsCotter Mill (heavymetals andradionuclides)into the LincolnPark areafrom privatewellsconnected to the publicwater supply and rely onprivate wellscontactuncertain. Although most residents aresupplied with townwater, documentsindicate that residents have beendrinking private well water as recentlyas 2002, and are permitted to usewells for unspecified domesticpurposes. However, it is believed thatwater from wells is used primarily forirrigation and other non-drinkingpurposes. Therefore, current andfuture use of water from private wellsis a potential exposure pathway.21Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentExposurePathwayExposure Pathway ElementsTimeFrameCommentsSources ofContaminationFate andTransportPoint ofExposureExposed PopulationRoute ofExposureSoil and SedimentCompleted Exposure PathwaySurface soil andTailings, dusts, andWindblownResidences andResidents, includingDermalPastPrior to remediation, contaminantsdust in Lincolnother wastes fromdust; soilpublic areaschildrencontact,were detected in soil from residentialParkthe Cotter Millirrigated bycontaminatedgroundwaterIncidentalingestion,Inhalationlawns and gardens. Therefore, contactwith contaminated soil in Lincoln Parkwas a past completed exposurepathway.Potential Exposure PathwaysSurface soil nearTailings, dusts, andWindblownThe ShadowGolfers at the public golfDermalPastSoils adjacent to the Cotter Mill havethe Cotter Millother wastes fromthe Cotter MilldustHills GolfCourse west ofthe Cotter Mill;along the countyroad leading tothe Cotter Millcourse; people on thecounty roadcontact,Incidentalingestion,InhalationCurrentFuturebeen contaminated by wind-blownparticulates. Therefore, contact withsoil near the Cotter Mill, especially atthe public golf course and along thecounty road, is a past, current, andfuture potential exposure pathway.Sediment inTailings, dusts, andTailings carriedAlong SandRecreational users;DermalPastThere were limited opportunities forSand Creekother wastes fromthe Cotter Millin surfacewater runoffCreekchildren playing alongSand Creekcontact,Incidentalingestionexposure since Sand Creek was notused for recreational purposes.Therefore, exposure to sediments priorto the Sand Creek Cleanup projectwas a past potential exposurepathway.Eliminated Exposure PathwaysSurface soil atTailings, dusts, andWindblownUnauthorizedNoneNonePastBecause the mill site itself is fencedthe Cotter Millother wastes fromthe Cotter Milldust; surfacewater runoffaccess is notallowedCurrentFutureand access is restricted, contact withon-site contamination is an eliminatedexposure pathway. Further,remediation efforts have removedsome impacted soils.22Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentExposurePathwayExposure Pathway ElementsTimeFrameCommentsSources ofContaminationFate andTransportPoint ofExposureExposed PopulationRoute ofExposureSurface soil andTailings, dusts, andWindblownCleanupNoneNoneCurrentDue to the sampling and remediationdust in Lincolnother wastes fromdust; soilactivitiesFuturein Lincoln Park, current and futureParkthe Cotter Millirrigated withcontaminatedgroundwaterhave eliminatedor reduced risksto acceptablelevelscontact with soil and dust is aneliminated exposure pathway.Sediment inSand CreekTailings, dusts, andother wastes fromthe Cotter MillTailings carriedin surfacewater runoffContaminatedsediment wasremoved fromSand CreekNoneNoneCurrentFutureSediment in Sand Creek is no longer ahazard since the completion of theSand Creek Cleanup project.Therefore, current and future contactwith sediment in Sand Creek is aneliminated exposure pathway.Surface WaterPotential Exposure PathwaySurface waternear the CotterMillTailings and otherwaste from theCotter MillSurface waterrunoff;transport fromSand Creek tothe ArkansasRiverAlong SandCreek betweenthe Cotter Milland theArkansas River;the DeWeeseDye Ditch; theArkansas RiverRecreational users(mostly in the ArkansasRiver, limitedrecreational use in SandCreek); people irrigatingwith water from theDeWeese Dye DitchIncidentalingestion,DermalcontactPastIn the past, surface water in SandCreek was found to contain elevatedlevels of metals and radionuclides.Therefore, past contact withcontaminated surface water near theCotter Mill was a potential exposurepathway.Eliminated Exposure PathwaySurface waternear the CotterMillTailings and otherwaste from theCotter MillSurface-waterrunoff;transport fromSand Creek tothe ArkansasRiverContaminationwas removedfrom SandCreekNoneNoneCurrentFutureDue to the construction of the SCSDam and the remediation of SandCreek, current and future contact withcontaminated surface water is aneliminated exposure pathway.23Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentExposurePathwayExposure Pathway ElementsTimeFrameCommentsSources ofContaminationFate andTransportPoint ofExposureExposed PopulationRoute ofExposureLocally Grown ProducePotential Exposure PathwayProduce grownTailings, dusts, andProduce grownOrchards andPeople who eat locallyIngestionPastBecause many Lincoln Park residentsin Lincoln Parkother wastes fromthe Cotter Millincontaminatedsoil or irrigatedwithcontaminatedwatergardens inLincoln Parkgrown produceCurrentFuturehave orchards and gardens, eatinglocally grown produce is a past,current, and future potential exposurepathway.Air EmissionsCompleted Exposure PathwayAmbient air nearGround-levelWindblownOff-site or down-People who live in theInhalationPastCotter’s air monitoring networkthe Cotter Millfugitive emissionsdust; stackwind locationsvicinity of Cotter Mill orFuturemonitors air concentrations at off-sitefacility(e.g., wind-blowndust) and elevatedpoint sources (e.g.,stacks)emissions intothe air andtransport to offsite locationsdownwind of the stacksPresentlocations. With the facility currently in“stand down” status, facility emissionsare now predominantly fugitive; airquality impacts should becharacterized by perimeter monitoringstations.24Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## IV. EVALUATION OF ENVIRONM ENTAL CONTAMINATION

A. Groundwater

Prior to 1980, Cotter disposed of waste in unlin ed ponds, which allowed contaminated liquids to

leach into the groundwater [EPA 2002]. Groundwater was shown to be contaminated as far away

as the Arkansas River, which is approxima tely 2.5 miles downgradient from the mill [EPA

2002]. Results from the 1984–1985 Remedial Inves tigation found that despite attempts at

remediation, the new, lined impoundments were leaking and the old ponds area was a continuing

source of groundwater contamina tion [GeoTrans 1986]. This study also found that a gap in the

ridge at the SCS Dam, built in 1971 across Sa nd Creek on the Cotter property, was allowing

shallow groundwater to move downg radient towards Lincoln Park, re sulting in concentrations of

molybdenum and uranium that were 2,000 times above background levels at that time.

Groundwater concentrations of mo lybdenum and uranium have decreased in recent years, but

concentrations have not yet retu rned to background levels in some wells [Weston 1998]. Figures

4 and 5 show the extent of the molybdenum and uranium concentrations, respectively, above

water quality standards (0.035 milligrams per lite r [mg/L] for molybdenum and 0.03 mg/L for

uranium). The highest levels in Lincoln Park were detected nearest to the Cotter property in the

vicinity of the DeWeese Dye Ditch [Weston 1998]. Additionally, despite remediation efforts, the

physical and chemical groundwater data suggest minor leakage from the primary impoundment

at the Cotter site [CDPHE 2007a; EPA 2002; USGS 1999b].

1. Remedial actions for controlling groundwater contamination

Since the early- to mid-1980s, remedial actions aimed at controlling groundwater contamination

and the spread of the resulting plume have take n place. Remediation has targeted the area along

the primary surface groundwater migration pathwa y, which runs parallel to Sand Creek [USGS

1999a]. Remediation has included the following:

 In the early 1980s, contaminated materials were moved into lined impoundments [EPA

2002].

 In 1988, a hydrologic clay barrie r was installed on the Cotter pr operty to help contain the

contaminated groundwater plume asso ciated with th e Cotter Mill.

 In 1989, a network of injection and withdrawal wells were construc ted downgradient of

the lined impoundment to reverse the hydrau lic gradient and prevent the northward

migration of contaminated groundwater. This system was discontinued in 2000, because

the system had little or no discernable e ffect on groundwater condi tions [CDPHE 2005].

 Dam to ditch flushing began in 1990. However, this effort was discontinued in 1996 due

to citizens’ concerns about contaminant concen trations rising in gr oundwater wells as the

plume was being flushed [CDPHE 2005].

 In 2000, a permeable reactive treatment wall was constructed across Sand Creek channel

in the DeWeese Dye Ditch flush, downstream of the SCS Dam [EPA 2002]. Although the

25Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### permeable reactive treatment wall has not pe rformed as anticipated, it is acting as a

barrier to additional groundwater flowing into Lincoln Park [Phil Egidi, CDPHE,

personal communica tion, July 2008].

These efforts have reduced groundwater contamin ation downgradient of the Cotter Mill [CDPHE

2008; EPA 2002; USGS 1999a], although the rate at which groundwater quality is being restored

is slower than anticipated [EPA 2007]. Cotte r and CDPHE continue to explore options for

cleaning the groundwater. Until a solution is reache d, contaminated groundwater is captured at

the SCS Dam and pumped back to the on-site lined impoundments [CDPHE 2008].

2. Nature and extent of groundwater contamination in Lincoln Park

CDPHE maintains a database containing enviro nmental sampling data from various sources

dating back to 1961. The most recent data entered into the database are from September 2007. To

evaluate exposures to residents of Lincoln Park, ATSDR identified data within the CDPHE

database for the wells reported to be in use during the 1989 water use survey (see Table 14 in

Appendix A). After discussions with a CDPHE re presentative, the following assumptions were

made while summarizing the data within the database.

 For chemicals, samples that were designated “Y ” in the detect flag column and contained

a zero in the result value column, but no valu e in the reporting detection limit column

were excluded from the summary statistics . For radionuclides, however, these samples

were included in the summary statistics si nce zero is considered a valid result.

 Samples that were designated “N” in the detect flag column and had the same value in the

result value column as the reporting dete ction limit column were included in the

summary statistics as 1⁄2 th e reporting detection limit.

 Negative result values for manganese and iron we re assumed to be not detected and were

included in the summary statistics as 1⁄2 the reporting detection limit.

 Negative values 2 

### for radionuclides were includ ed in the summary statistics.

a) Wells used for personal consumption

The 1989 Lincoln Park Water Use Survey identified seven When this document was written, 

### wells used for personal consumption (IMS 1989). Data for data from EPA’s 2008 water use 

### six of the wells are available in the CDPHE database (see survey were not yet available.



### Table 14). The seventh well had a broken pump at the time ATSDR will update well use

information when the data are 

### of the survey [IMS 1989]; no data for this well appear to be

available. 

### in the database. The data fo r wells reportedly used for

personal consumption in 1989 are summarized in Table 15.

Samples were collected intermittently from 1984 to 2007. The locations of these wells are shown

in Figure 6. With the exception of molybdenum and uranium, the data are limited (e.g., only two

wells were sampled for the majority of the chem icals and none were sampled for radionuclides).

2 Negative values for radionuclides occur when samples are not much different from background, since standard

protocol is to subtract background radioactivity from the sample count.

26Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### However, all six wells were repeatedly tested for molybdenum and uranium, which were the only

chemicals detected above comparison values (see Table 15). Of the personal consumption wells,

Well 189 contains the highest molybdenum and uranium concentrations. Well 189 is the only

well with levels of uranium c onsistently detected above the comparison value (see Figure 6).

It is difficult to evaluate the molybdenum and uranium data over time, because of the limited

sampling data for these wells and the inconsiste ncy of sampling the same wells over time. The

molybdenum and uranium concentrations in th e personal consumption wells over time are

graphically shown in Figure 7 and Figure 8 in Appendix B, respectively. Well 168 (house well

on Grand Avenue) 3 

### and Well 189 (house well on Hickory) 4 

### were sampled the most frequently.

No clear pattern of decreasing con centrations from 1984 to 2007 exists.

The USGS identified Well 10 (So. 12th St.) and We ll 114 (Pine) as representative of background

for the Lincoln Park area [Weston 1998]. The data available in the CDPHE database for these

two wells are summarized in Table 16. 5 

### The average concentration of molybdenum in the wells

used for personal consumption (0.082 mg/L; see Table 15) is higher than the average

concentration found in the background wells (0. 023 mg/L; see Table 16). The average uranium

concentration in the wells used for personal consumption (0.028 mg/L; see Table 15) is only

slightly higher than the average concentration in the backgr ound wells (0.021 mg/L; see Table

16).

(1) Grand Avenue Well

In a 2002 newspaper article, a resi dent on Grand Avenue reported drinking water from their well

[Plasket 2002]. Limited data (1 to 20 samples) are available in the CDPHE database for this

location (see Figure 6). Samples were collected and analyzed for most chemicals in 1984, and

then from either 2004 or 2005 to 2007. Samples from this well were also tested for molybdenum

and uranium from 1988 to1991. The water from this well was tested for several chemicals, but

not for radionuclides. None of the samples dete cted chemicals above comparison values (see

Table 17).

b) Wells used to irrigate fruit and vegetable gardens

The 1989 Lincoln Park Water Use Survey identified 22 When this document was written,



### wells used to irrigate fruit and 21 wells used to irrigate data from EPA’s 2008 water use



### vegetable gardens [IMS 1989]. 6 

### Data for 28 of these wells survey were not yet available.

ATSDR will update well use 

### are available in the CDPHE database (see Table 14). information when the data are 

### Samples were sporadically collected from these wells and available. 

### analyzed for various chemicals between 1962 and 2007.

Samples were collected and anal yzed for radionuclides from

3 There are five non-detected molybdenum values for Well 168. Four of them are most likely due to the detection

limit being too high for the level of molybdenum in that we ll. The detection limits were 0.01 mg/L for three of the

samples and 0.05 mg/L for one of the samples. The concentrations in that well hover around 0.01 mg/L.

4 One of the non-detected molybdenum concentrations in Well 189 is unexplainable. The detection limit (0.01 mg/L)

is low enough to have detected the level of molybdenum typically found in the well. The detection limit (0.5 mg/L)

for the other non-detected concentration is too high for the level of molybdenum typically found in the well.

5 Groundwater samples from the background wells were not tested for radionuclides.

6 Some wells were used for both purposes.

27Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 1995 to 2000. The data for wells reportedly used to irrigate fruit and vegetable gardens in 1989

are summarized in Table 18 (chemicals) and Ta ble 19 (radionuclides). Th e locations of these

wells are shown in Figure 9. The data for thes e wells are much more robust than the data

available for the wells used for personal consum ption, in part due to the increased number of

wells. Molybdenum and uranium were sampled in all 28 wells used for irrigation. Five wells

were tested for radionuclides.

The maximum concentrations in the wells used to irrigate fruit and vegetable gardens exceeded

the comparison values for molybdenum, selenium, sulfate, total dissolved solids, and uranium.

The average concentrations exceeded comparison values only for molybdenum, total dissolved

solids, and uranium. Looking at data from 2000 to 2007, only the average molybdenum

concentration (0.1 mg/L) continued to exceed the comparison value.

The average concentration of molybdenum in th e wells used to irrigate fruit and vegetable

gardens (0.99 mg/L; see Table 18) is higher than the average concentration found in the wells

that USGS identified as background for Lincoln Park (0.023 mg/L; see Table 16). Similarly, the

average uranium concentration in the wells used to irrigate fruit and vegetable gardens (0.13

mg/L; see Table 13) is higher than the aver age concentration in the background wells (0.021

mg/L; see Table 16). The average concentration for total dissolved solids in the wells used to

irrigate fruit and vegetable gardens (550 mg/L; se e Table 18) is also higher than the average

concentration found in the backgrou nd wells (429 mg/L; see Table 16).

c) Wells used to water livestock

The 1989 Lincoln Park Water Use Survey identified 22 When this document was written,



### wells used to water livestock [IMS 1989]. Data for 19 of data from EPA’s 2008 water use

survey were not yet available. 

### these wells are available in the CDPHE database (see Table ATSDR will update well use 

### 14). Samples were sporadically collected from these wells information when the data are 

### and analyzed for various chemicals between 1962 and available 

### 2007. Samples were collected and analyzed for

radionuclides from 1995 and 1996. The data for wells

reportedly used to water livestock in 1989 are summarized in Table 20 (chemicals) and Table 21

(radionuclides). The locati ons of these wells are shown in Figure 10. Only one to four wells were

sampled for the majority of the chemicals, how ever, molybdenum and uranium were sampled in

all 19 wells used to water livestock. Two wells were tested for radionuclides.

The maximum concentrations exceeded the comp arison values for molybdenum, sulfate, total

dissolved solids, and uranium. The average conc entrations only exceeded comparison values for

molybdenum and uranium. Looking at data from 2000 to 2007, only the average molybdenum

concentration (0.08 mg/L) continued to exceed the comparison value.

The average concentration of molybdenum in the wells used to water liv estock (0.212 mg/L; see

Table 20) is an order of magnit ude higher than the av erage concentration f ound in the wells that

USGS identified as background for Lincoln Pa rk (0.023 mg/L; see Table 16). The average

uranium concentration in the well s used to water livestock (0. 034 mg/L; see Table 20) is higher

than the average concentration in the background wells (0.021 mg/L; see Table 16).

28Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### d) Wells used to water lawns

The 1989 Lincoln Park Water Use Survey identified 42 When this document was written,



### wells used to water lawns [IMS 1989]. Data for all 42 data from EPA’s 2008 water use

survey were not yet available. 

### wells are available in the CDPHE database (see Table 14). ATSDR will update well use 

### Samples were sporadically collected from these wells and information when the data are 

### analyzed for various chemicals between 1962 and 2007. available. 

### Samples were collected and analyzed for radionuclides

from 1995 to 2000. The data for wells reportedly used to

water lawns in 1989 are summarized in Table 22 (c hemicals) and Table 23 (radionuclides). The

locations of these wells are shown in Figure 11. Several wells were sampled for each chemical,

and molybdenum and uranium were tested in all 42 wells used to water lawns. Seven wells were

sampled for radionuclides.

The maximum concentrations exceeded the comparison values for chloride, molybdenum,

selenium, sulfate, total dissolved solids, and uranium. The average concentrations exceeded

comparison values for molybdenum, sulfate, total di ssolved solids, and uranium. Looking at data

from 2000 to 2007, only the average molybdenum con centration (0.1 mg/L) continued to exceed

the comparison value from 2000 to 2007, while the average uranium concentration (0.03 mg/L)

was at the comparison value.

The average concentration of molybdenum in wells used to water lawns (2.2 mg/L; see Table 22)

is two orders of magnitude highe r than the average concentrati on found in the wells that USGS

identified as background for Lincoln Park (0.023 mg/L; see Table 16) . The average sulfate

concentration in wells used to water lawns (351 mg/L; see Table 22) is almost six times higher

than the average concentrati on in the background wells (61 mg/L; see Table 16). The average

concentration for total dissolved solids in wells used to water lawns (746 mg/L; see Table 22) is

higher than the average concen tration found in the background wells (429 mg/L; see Table 16).

The average dissolved uranium concentration in wells used to water lawns (0.233 mg/L; see

Table 22) is an order of magn itude higher than the average concentration in the background

wells (0.021 mg/L; see Table 16).

(1) Well 138

Well 138 (field well on Cedar Street; see Figure 11) was identified during the 1998 Supplemental

Human Health Risk Assessment as the maximally impacted off-site well [Weston 1998]. In 1989,

Well 138 was used only to water the lawn [IMS 1989] . Adequate data for this well are available

in the CDPHE database. Samples were collect ed from Well 138 and analyzed for various

chemicals between 1968 and 2000. Samples were colle cted and analyzed for radionuclides from

1995 to 2000. The data for Well 138 are summarized in Table 24 (chemicals) and Table 25

(radionuclides).

The maximum concentrations exceeded the comparison values for chloride, molybdenum,

selenium, sulfate, total dissolved solids, and ur anium. The average concentrations also exceeded

comparison values for molybdenum, sulfate, total dissolved solids, and uranium. A clear

29Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### decrease in concentrations o ccurred over time for molybdenum (see Figure 12), selenium (see

Figure 13), and uranium (see Figure 14).

Well 138 has higher levels of cont amination than the wells that USGS identified as background

for Lincoln Park. The average concentration of molybdenum in Well 138 (8.0 mg/L; see Table

244) is hundreds of times higher than the aver age concentration found in the background wells

(0.023 mg/L; see Table 16). The average sulf ate concentration in Well 138 (1,059 mg/L; see

Table 24) is considerably higher than the av erage concentration in the background wells (61

mg/L; see Table 16). The averag e concentration for total diss olved solids in Well 138 (1,530

mg/L; see Table 24) is three times higher th an the average concen tration found in the

background wells (429 mg/L; see Table 16). The av erage dissolved uraniu m concentration in

Well 138 (0.73 mg/L; see Table 24) is more than an order of magnitude higher than the average

concentration in the background wells (0.021 mg/L; see Table 16).

e) Groundwater trends over time

To evaluate the levels of molybdenum, sele nium, and uranium in groundwater over time,

ATSDR combined and graphed all the groundwater data for the wells used for personal

consumption, irrigating fruit and vegetables, wa tering livestock, and watering lawns (Figures 15

through 17 in Appendix B). Figure 15 shows a pattern of decreasing concentrations of

molybdenum in groundwater over time. The concentrations of selenium seem to hold steady, but

do decrease slightly over time (see Figure 16). Th e concentrations of uranium also clearly

decrease over time (see Figure 17).

B. Soil and sediment

1. Background levels

Cotter was required by the 1988 RAP to establish bac kground levels of certain elements in soils

and sediments. Twenty soil samples were collected from five sub-basins considered free from

mill-related contamination to represent natura l background typical of the area near the mill

[HRAP 1991]. Table 4 below presents the results of that study, which were further supported by

additional sampling [CDPHE 2005].

Table 4. Background soil and sediment levels

Soil Sediment

Average Upper

Confidence

Limit Average Upper

Confidence

Limit

Molybdenum 2.4 ppm 4.6 ppm 2.3 ppm 4.7 ppm

Uranium 2.1 ppm 2.9 ppm 2.0 ppm 3.4 ppm

Radium-226 1.3 pCi/g 1.9 pCi/g 1.1 pCi/g 1.7 pCi/g

Thorium-230 1.8 pCi/g 3.2 pCi/g 1.5 pCi/g 3.1 pCi/g

Gamma Exposure Rates 9.4 μR/hr

-­ -­ -­

Source: CDPHE 2005; HRAP 1991

pCi/g – picocuries per gram

ppm – parts per million

μR/hr – microroentgen per hour

30Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 2. Off-site soil contamination and remediation

As part of the 1988 RAP, Cotter was required to su rvey soils outside the restricted area (the

fenced active mill site) and to remediate contaminated soils with levels of radium and

molybdenum that are above the esta blished background [CDPHE 2005].

As part of the 1998 Supplemental Human Health Risk Assessment [Weston 1998], Weston (a

contractor for Cotter) collected surface soil samples (0-2 inches) from eight zones around the

mill property (see Figure 18 in Appendix B). Each zone was divided into 8 to 12 grids. Four

samples were collected near the center of each grid and were composited (i.e., combined and

homogenized) to form a single representative sample [Weston 1998]. The results of this

sampling are shown in Table 26 (chemicals) and Table 27 (radionuc lides). The maximum

concentrations exceeded the comparison values for arsenic 7 

### in all eight zones, for cadmium in all

zones except one (D), for lead in three zones (F, G, and H), and for radium-226 in four zones (A,

B, C, and E). The average concentrations also exceeded comparison values for arsenic 7 

### in all

eight zones, for cadmium in one zone (F), for le ad in one zone (H), and for radium-226 in two

zones (A and B). The average radium-226 and thor ium-230 concentrations were higher than the

established average background levels in all eight zones (see 4 for background).

Cotter has occasionally hauled ore and other materi als by truck to the site for processing at their

facility. To assess the potential th at material has been lost alo ngside the county road leading to

the mill and the access road entering the mill s ite, MFG (a contractor to Cotter) scanned the

county road (assuming CR 143) from the road lead ing to the Shadow Hills Golf Course to the

Cotter Mill access road for gamma radiation (see

There is limited potential for exposure to 

### Figure 19). They also collected soil samples to

contaminants along the access road 

### establish a correlation be tween the gamma exposure since access to the Cotter Mill is 

### rate and the concentration of gamma emitters in the restricted and soils along the access road 

### soil. A total of 16 locations were sampled—five were remediated in 2007 and 2008.



### along the county road, five along the mill’s access

road, and six from background locations. The locatio ns were not chosen to estimate an average

concentration, but rather to provide data for a ra nge of gamma exposure rates. Each sample was a

composite of 10 aliquots within a 100 x 100 mete r area [MFG 2005]. The results of this sampling

are shown in Table 28. The maximum and average radium-226 and natural uranium

concentrations exceeded the comparison values for samples taken along the mill’s access road.

The maximum and average radium-226 concentra tions also exceeded the comparison value for

samples taken along the county road. Average concen trations of all radionuclides sampled were

higher along the county road and the mill’s access road than from those areas designated as

background (see Table 28).

To address public concerns a bout the impact of the Cotter Mi ll on the health of Cañon City

residents, CDPHE collected 21 soil samples in January 2003 [CDPHE 2003]. Each sample was a

composite of 30–40 scrape samples 8 

### from each location. Seven samples from Lincoln Park were

7 The 1998 Supplemental Human Health Risk Assessment found no discernible spatial pattern for arsenic around the

Cotter Mill, indicating that arsenic levels have not been measurably altered by airborne releases from the mill

(Weston 1998).

8 Surface soil samples were collected using a method developed specifically to look for airborne contamination that

settled to the ground (CDPHE 2003).

31Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### collected, including one sample of suspected flood sediment (Pine Street near Elm Avenue), two

samples of dust (one from a barn loft and one from a residential attic) , and four samples of

surface soil (one from the Mc Kinley Elementary School playground). Seven samples were

collected from areas east of the mill, includ ing the Brookside Head Start School. Six samples

were collected from areas west of the mill, including a private residence. One sample was

collected from the extreme northern part of Cañon City to represen t the regional background

(corner of Orchard Avenue and High Street). The sampling event was intentionally biased

toward finding the highest amounts of contamina tion possible [CDPHE 2003]. Sample locations

are shown in Figure 20. The data from this sampling event are summarized in Table 29

(chemicals) and Table 30 (radionuclides). The maximum concentrations for lead and radium-226

exceeded the comparison values. The average co ncentration for lead also exceeded the

comparison value. The average concentration for radium-226 did not exceed the comparison

value.

Since 1994, Cotter has been annually collecting surface soil samples (0–6 inches) at 10

environmental air monitoring stations that ar e located along the fac ility’s boundary and in

residential areas (see Figure 21). From 1979 to 1993, soils were collected every 9 months. The

data from this effort are summarized in Tabl e 31. The maximum concentration for radium-226

exceeded the comparison value; however, the average concentration of samples over the

timeframe did not.

a) The nearest resident

The nearest resident is located 0.25 mile from the restricted area [Galant et al. 2007]. One of the

air monitoring stations annually monitored by Cotte r was established as “the nearest resident”

(AS-212). This location is between the Cotter Mi ll and an actual reside nce [Cotter 2007]. The

limited data for this location are shown in Tabl e 32 (chemicals) and Table 33 (radionuclides).

The maximum concentration for radium-226 ex ceeded the comparison value; however, the

average concentration did not.

b) Lincoln Park

As part of the 1988 RAP, Cotter was required to EPA determined that sediment and soil in 

### conduct a gamma scintillometer survey in Lincoln Lincoln Park are no longer an issue since



### Park to evaluate whether soils had been the completion of the Sand Creek Cleanup

project in 1998 [EPA 2002, 2007]. 

### contaminated by windblown and waterborne

contaminants from the facility. In December 1988,

127 scintillometer readings were taken near inte rsections in Lincoln Park. The average external

gamma radiation for Lincoln Park was 9.8 microroe ntgen per hour (μR/hr), which is considered

to show “no elevated gamma in Linc oln Park” [CDPHE 2005; HRAP 1991].

As part of the 1996 Supplemental Human Health Risk Assessment [Weston 1996], Weston

compiled data from several past so il studies, including the following:

 Samples collected at the air monitoring location in Lincoln Park in 1987 and 1988

32Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



###  Samples collected from yards of 10 participants in the Lincoln Park water use survey in

1989

 Samples collected from residential gardens in Lincoln Park in 1990

 Samples collected from lawns and gardens in Lincoln Park in 1996

The data from these studies are collectively su mmarized in Table 34 (chemicals) and Table 35

(radionuclides). Only the maximum and averag e concentrations for arsenic exceeded the

comparison value.

The soil samples collected from yard s of the participants in the 1989 Lincoln Park water use

survey were also analyzed for molybdenum and uranium. The average molybdenum

concentration was 2.0 ppm and the average ur anium concentration was 2.8 ppm [HRAP 1991].

The samples collected as part of the 1990 resident ial garden soil survey we re also analyzed for

molybdenum. The average concentration was 0.13 ppm [HRAP 1991]. These concentrations are

well below the comparison values for mol ybdenum (300 ppm) and uranium (100 ppm). 9



### As part of the 1998 Supplemental Human Health Risk Assessment [Weston 1998], 73 surface soil

samples were collected from lawns (0–2 inches) and gardens (0–6 inches) in Lincoln Park. For

sampling purposes, Lincoln Park was divided in to seven areas and 6–16 samples were taken

from each area [Weston 1998]. The results of this sampling are shown in Table 26 (chemicals)

and Table 27 (radionuclides). Only the maximu m and average arsenic concentrations exceeded

the comparison value.

The effect of irrigation with contaminated well water on the levels in the soil was also examined

during the 1998 Supplemental Human Health Risk Assessment [Weston 1998]. The soil samples

from Lincoln Park were divide d into two categories—those irri gated with well water that had

been impacted by mill releases and those not belie ved to have been irrigated with contaminated

well water. These data are shown in Table 36 (chemicals) and Table 37 (radionuclides). The

concentrations of arsenic, molybdenum, and uran ium were statistically higher in soil samples

irrigated with impacted well water [Weston 1998].

(1) Lead in Lincoln Park

Residents of Lincoln Park expre ssed concerns about lead contamin ation in soil and dust due to

historical and current mining and milling operations in the area. Six potential sources of lead are

located near the community of Lincoln Park—the Cotter Mill, the Empire Zinc Smelter (also

known as New Jersey Zinc and the College of the Cañons), the US Smelter Facility, the Cañon

City Copper Smelter, the Ohio Zinc Compa ny, and the Royal Gorge Smelter [EPA 2004]. The

Lincoln Park neighborhood is located generally east- southeast of these faci lities and the general

wind direction is west to east.

To address the residents’ concerns, EPA requested that ATSDR assess the health risk associated

with lead contamination in Linc oln Park. After a site visit and discussions with the community,

9 The data for molybdenum and uranium are not summarized in Table because the raw data for these two chemicals

are not presented in the 1996 Supplemental Human Health Risk Assessment (Weston 1996).

33EPA’s report documenting the residential soils

sampling project can be accessed at the following site:

http://www.epa.gov/region8/superfund/co/lincolnpark/

. Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### ATSDR focused assessments on two primary issues—1) blood lead levels in children living in

Lincoln Park and 2) lead contaminat ed dust in homes in Lincoln Park.

ATSDR reviewed the available data on blood lead le vels in children and concluded that the rate

of elevated blood lead levels fo r Fremont County is below the state average. However, it was not

possible to evaluate whether area children, including “high risk” children, were being adequately

screened for blood lead levels [ATSDR 2006a]. To further assess bl ood lead levels, ATSDR

tested the blood level of 115 “at risk” school children in 2005. None of the children had elevated

blood lead levels [ATSDR 2006b].

ATSDR reviewed the available data on lead leve ls in household dust and found the data to be

sparse and/or lacking. ATSDR

conducted a screening level evaluation

of the available dust samples and

concluded that the data were not

sufficient to determine the magnitude or extent of the potential hazard associated with levels of

lead in household dust [ATSDR 2006c]. To furthe r assess the health impacts in Lincoln Park,

ATSDR, in collaboration with the Colorado Citizens Against Toxic Waste (CCAT) and EPA,

collected and analyzed 44 indoor dust sample s, 80 surface soil samples (0–2 inches or 0–6

inches) from 22 properties, and 45 blood samples. The results of this e xposure investigation did

not indicate the presence of unusual levels of lead in residen tial indoor dust samples, the soil at

those homes, or in the blood of occ upants of those homes [ATSDR 2006d].

c) Sand Creek

Sand Creek is primarily an ephemeral creek that passes through the Cotte r Mill and runs northnortheast through Lincoln Park. It becomes pe rennial for the last 0.25–0.5 mile before its

confluence with the Arkansas River. Prior to th e construction of the SCS Dam north of the Cotter

Mill in 1971, surface water and sediment from the facility flowed down the Sand Creek drainage

into Lincoln Park [CDPHE 2005; GeoTrans 1986]. Mill tailings in the Old Tailings Pond Area

are the source of the mill-derived contaminants (primarily radium-226 and thorium-230) in Sand

Creek [Cotter 2000].

During the 1986 Remedial Investigation [GeoTrans 1986], sediment samples were collected from

the following locations in Sand Creek to evaluate present (i.e., 1985) a nd historical loadings

from the Cotter Mill.

 SD01 – mouth near the Arkansas River

 SD02 – near spring where flow begins (refl ects migration of contaminants in the

groundwater)

 SD04 – below the SCS Dam in

(1) an abandoned stock watering pond (forme d by diversion of runoff water into a

depression adjacent to Sand Creek)

(2) in drainage (reflects historic al picture of uncontrolled emissions)

(3) in drainage above #2 (reflects histor ical picture of uncontrolled emissions)

34Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



###  SD05 – above the SCS Dam adjacent to the west property edge

The results of this sampling are presented in Ta ble 38 and Table 39. Only the concentrations for

arsenic and radium-226 exceeded ATSDR’s comparison values.

As part of the 1988 RAP, Cotter was required to evaluate the mill’s potential impacts to Sand

Creek and remove sediments that exceeded th e radium-226 cleanup goal of 4.0 picocuries per

gram (pCi/g), which allows unrestricted use of the creek [Cotter 2000]. A total of 721 samples

were systematically collected along the 1.25 mile stretch from just north of the Cotter Mill to

where Sand Creek becomes perennial (see Figure 22). Surveying and cleanup began in the spring

of 1993 and continued until remediation was completed in December 1998. Approximately 9,000

cubic yards of soil were removed from Sand Cr eek and disposed of on Cotter property [Cotter

2000]. The excavated areas were backfilled with clean soil [CDPHE 2005]. Thirty confirmatory

samples established that the av erage site-wide radium-226 con centration was 1.5 pCi/g (below

the cleanup goal of 4.0 pCi/g) a nd the average site-wide thor ium-230 concentration was 3.9

pCi/g after remediation [Cotter 2000]. In additi on to the sampling and remediation for radium

226, seven of the confirmation samples were an alyzed for 10 chemicals in 1998 [Cotter 2000].

These results are presented in Table 40. Only the maximum and average concentrations for

arsenic exceeded ATSDR’s comparison value.

At the time of mill closure, Cotter was required by the 1988 RAP to survey molybdenum and radium

226 in sediments in the perennial stream segm ents of Sand Creek and Willow (Plum) Creek to

determine whether these areas hav e been impacted by the mill. If necessary, s ediments above

background will be removed and properly disposed of (CDPHE 2005). ­



### d) The Fremont Ditch

The Fremont Ditch system is downstream of Sand Creek. It diverts water from near the

confluence of Sand Creek and the Arkansas Ri ver downgradient toward Florence. The ditch

receives substantial amounts of water from Sand Creek during low flows in the Arkansas River.

During these periods, any contaminants moving dow n Sand Creek would likely be transported to

Fremont Ditch [GeoTrans 1986].

As part of the 1988 RAP, Cotter wa s also required to conduct a gamma survey of the dry beds of

the Fremont Ditch. Cotter sampled sediment in Fremont Ditch from its head gate near Sand

Creek to about a quarter mile downstream. The average radium-226 level was 1.86 pCi/g, which

was below the cleanup standard of 4 pCi/g. The state agreed with Cotter that the Fremont Ditch

did not require remediation because the concentr ations of gross alpha (3.8 pCi/g), uranium (6.6

ppm), and molybdenum (2.2 ppm) were also low [CDPHE 2005].

C. Surface water

1. Nature and extent of contamination

The Cotter Mill is a non-discharge facility, mean ing that Cotter does not release wastewater to

the surface water system. All remediation wa ter is pumped to on-site impoundments for

35Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### evaporation or recycling. Howe ver, prior to construction of the SCS Dam in 1971, storm events

carried contaminated surface water and sedime nts from the facility down the Sand Creek

drainage [CDPHE 2005]. One event in partic ular, a flood in June 1965, caused the unlined

tailings ponds at the Cotter Mill to overflow into Lincoln Park. Sediment in the Lincoln Park

portion of Sand Creek was contaminated with tai lings that were carried in surface water runoff

from the mill [EPA 2007].

CDPHE maintains a database containing surface The SCS Dam was built to prevent 

### water monitoring data dating back to 1962. The surface water and sediment from flowing



### most recent data entered in to the database are from into Lincoln Park during storm-generated

floods. Since the construction of the dam, 

### September 2007. To evaluate exposures to people Lincoln Park no longer receives runoff 

### living near the Cotter Mill, ATSDR extracted from the Cotter Mill. Additionally, since 

### surface water data collec ted from Sand Creek, the 1979, impounded water collected at the 

### DeWeese Dye Ditch, and the Arkansas River. After dam has been pumped back to the lined



### discussions with a CDPHE representative, the impoundment on site [EPA 2002;

GeoTrans 1986; HRAP 1991]. 

### following assumptions were made while

summarizing data within the database.

 Samples that were designated “N” in the detect flag column and had the same value in the

result value column as the reporting dete ction limit column were included in the

summary statistics as 1⁄2 th e reporting detection limit.

 Negative result values for manganese and iron we re assumed to be not detected and were

included in the summary statistics as 1⁄2 the reporting detection limit.

 Negative values 10 

### for radionuclides were includ ed in the summary statistics.

a) Sand Creek

From 1993 to 1998, Cotter conducted the Sand Creek Cleanup project to identify and remove

mill tailings that had moved into the creek bed as the result of surface water runoff from the

Cotter Mill prior to the construction of the SCS Dam. Sediments above the radium-226 cleanup

goal of 4.0 pCi/g were removed, which allows unre stricted use of the cr eek [Cotter 2000; EPA

2002].

Two locations in Sand Creek—one at Ash Street (008) and one at th e confluence with the

Arkansas River (506)—are sampled as part of the surface water mon itoring program (Cotter

2007). The CDPHE database contains surface wate r monitoring data from these two locations,

which are summarized in Table 41 (chemicals) and Table 42 (radionuclides). The maximum

concentrations for manganese, molybdenum, sulf ate, and total dissolv ed solids exceeded the

comparison values. However, for all four of th ese chemicals, only the maximum concentrations

exceeded comparison values—the second highest detected concentrations were below

comparison values. None of the average c oncentrations exceeded comparison values.

10 Negative values for radionuclides occur when samples are not much different from background, since standard

protocol is to subtract background radioactivity from the sample count.

36Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### As part of the 1991 Health Risk Assessment of the Cotter Uranium Mill Site [HRAP 1991], the

Health Risk Assessment Panel (HRAP) revi ewed over 18,000 samples collected from 1976–

1989, from 55 different surface water locations. More than 95% of the surface water data were

collected from 10 main locations. The location in Sand Creek at Ash Street (008, formerly

known as 555) was one of these locations. The average molybdenum (0.009 mg/L) and uranium

(0.016 mg/L) concentrations from this locati on were well below the comparison values

(molybdenum: 0.035 mg/L; uranium: 0.03 mg/L). 11



### b) DeWeese Dye Ditch

The DeWeese Dye Ditch is an irrigation ditch that flows between the Cotter Mill and Lincoln

Park. The ditch diverts water from Grape Creek to irrigate about 1,200 acres during the summer

growing period [GeoTrans 1986]. Th e ditch crosses Sand Creek downstream from the SCS Dam,

but does not join it. Seepage from the ditc h recharges groundwater within the Sand Creek

drainage. This process dilutes and flushes th e contaminated groundwater under Lincoln Park

[EPA 2002].

The CDPHE database contains su rface water monitoring data from two locations in the DeWeese

Dye Ditch—one upstream of the confluence with Fo rked Gulch (520) and one at Cedar Avenue

(526). The location at Cedar Avenue is sampled as part of the surface water monitoring program

[Cotter 2007]. The data for both locations are summarized in Ta ble 43 (chemicals) and Table 44

(radionuclides). The maximum concentrations exceeded the comparison values for iron,

manganese, total dissolved solids, and dissolved uranium. However, for iron and manganese,

only the maximum concentrations exceeded comp arison values—the second highest detected

concentrations were below comparison values. Only three of the total di ssolved solids samples

and three of the dissolved uranium samples were detected above comparison values. None of the

average concentrations exceeded comparison values.

Molybdenum and uranium data from 1984 to 1989, from the same two locations in the DeWeese

Dye Ditch (520 and 526), are summarized in the 1991 Health Risk Assessment of the Cotter

Uranium Mill Site (HRAP 1991). The average molybdenum and uranium concentrations were

well below the comparison values (see Table 5 below).

Table 5. Average molybdenum and uranium co ncentrations in the DeWeese Dye Ditch

Chemical Average concentration at

Location 520 (mg/L) Average concentration at

Location 526 (mg/L) Comparison Value

(mg/L)

Molybdenum 0.003 0.003 0.035

Uranium 0.002 0.0019 0.03

Source: HRAP 1991

Molybdenum data that were several orders of magnitude greater than any other observed sample (i.e., outliers) were

not used to calculate the averag e concentrations (HRAP 1991).

It was not possible to determine whether these data are included in the CDPHE database.



### c) Arkansas River

11 It was not possible to determine whether these data are included in the CDPHE database.

37Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment

The Arkansas River sampling plan was

approved by the CDPHE Water Quality

Control Division [CDPHE 2005]. 

### From April 1989 to June 1990, Cotter and their

consultant, Western Environmental Analysts,

conducted bi-weekly sampling in the Arkansas River

at the following five locations:

1. Parkdale (background)

2. Grape Creek

3. 1 st 

### Street (upstream of where Sand Cr eek enters the Arkansas River)

4. Mackenzie Avenue Bridge (downstream from where Sand Creek enters the Arkansas

River)

5. Where Highway 67 to Florence crosses the river

Water, sediment, autotrophs (algae), pr imary consumers/detrivores (tadpoles,

macroinvertebrates), and carnivores (fish) were collected and tested for molybdenum, uranium,

radium-226, and thorium-230. Extremely low concen trations were detected, which indicated no

statistical evidence of an increase in contam ination downstream on the Arkansas River [CDPHE

2005].

In addition, four synoptic sampling events (i.e ., sampling of water in -flows) were conducted

between Canyon Mouth and Highway 67. The purpose of the synoptic sampling was to

determine whether tributary flows reflect unu sual sources of uranium or molybdenum. The

sampling showed that other sources such as F ourmile Creek, as well as Sand Creek and Plum

Creek, contribute to increases in the Arkansas River [CDPHE 2005].

Two locations in the Arkansas Rive r—one upstream of Sand Creek at 1 st 

### Street (907) and one

downstream of Sand Creek at Mackenzie Avenue (904)—are sampled as part of the surface

water monitoring program [Co tter 2007]. The CDPHE database contains surface water

monitoring data from these two locations, whic h are summarized in Table 45 (chemicals) and

Table 46 (radionuclides). At both locations, the maximum concentrations exceeded the

comparison value for sulfate. The maximum concen tration for total dissolved solids exceeded the

comparison value for the upstream location, bu t not the downstream location. In all three

instances, these maximum concentrations appear to be outliers and are the only concentrations

that exceeded comparison values—the second highest detected concentrations were below

comparison values. The maximum concentration for molybdenum also exceeded the Colorado

state groundwater standard for th e upstream location, but not th e downstream location. None of

the average concentrations exceeded comparison values.

Data from 1984 to 1989, from two locations in the Arkansas River—one upstream of Sand Creek

near Grape Creek (502) and one downstream of Sand Creek near Fourmile Bridge (504)—are

summarized in the 1991 Health Risk Assessment of the Cotter Uranium Mill Site [HRAP 1991].

The average molybdenum and uranium concentra tions were well below the comparison values

(see Table 6 below).

38Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 6. Average molybdenum and uranium concentrations in the Arkansas River

Chemical Average concentration

upstream of

Sand Creek near Grape

Creek (502) (mg/L) Average concentration

downstream of

Sand Creek near Fourmile

Bridge (504) (mg/L) Comparison

Value (mg/L)

Molybdenum 0.00391 0.0056 0.035

Uranium 0.00532 0.00574 0.03

Source: HRAP 1991

Molybdenum data that were several orders of magnitude greater than any other observed sample (i.e., outliers) were

not used to calculate the averag e concentrations (HRAP 1991).



### d) Willow Lakes

The Willow Lakes are comprised of several sma ll ponds near the Arkansas River in the Willow

Creek watershed, which lies directly to the east of the Sand Creek watershed. The Willow Lakes

receive water from shallow groundwat er and surface runoff [HRAP 1991].

Cotter was required by the 1988 RAP to evalua te whether the Willow Lakes had been

contaminated by the mill. Water, sediment, auto trophs (algae), primary consumers/detrivores

(tadpoles, macroinvertebrates), and carnivores (fish) from the Willow Lakes and three

comparison lakes were collected and tested for molybdenum, uranium, and radium. The

information showed that the Willow Lakes ha d not been contaminated by the Cotter Mill

[CDPHE 2005].

D. Locally grown produce

1. Nature and extent of contamination

As part of the 1996 Supplemental Human Health Risk Assessment (Weston 1996), Weston

compiled available food data from several past studies. Samples included chicken meat, fruit

(apples, cherries, grapes), and ve getables (asparagus, carrots, lettuce, tomatoes, turnips). The

local samples were compared to food collected from supermarkets. The data are presented in

Table 47 and Table 48 in Appendix A. The limited sample data suggest that the chemicals and

radionuclides found in the foods are probably natu ral in origin, however, it was not possible to

exclude the possibility that some food types ma y be influenced by mill-related contaminants

[Weston 1996].

To further evaluate exposures to residents w ho eat locally grown fruits and vegetables, a

sampling program was initiated in Lincoln Park during the 1998 Supplemental Human Health

Risk Assessment [Weston 1998]. People were asked to donate locally grown produce samples for

analysis. The fruits and vegetables sampled are presented in the table below. The samples were

tested for heavy metals and radionuclides. The analytical results of the sampling program are

summarized in Table 49 and Table 50 in Appendix A.

39Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment

Fruits Sampled Vegetables Sampled

Apples Acorn squash Green Beans Rhubarb

Cantaloupe Beets Green Onions Squash

Grapes Carrots Kohlrabi Tomatoes

Honey dew melon Celery Patty pan squash Turnip Greens

Plums Corn Peppers Turnips

Watermelon Cucumbers Pumpkin Winter squash



### The samples were divided into two categories— (1) produce that was grown in soil known to

have been irrigated with contaminated well wa ter (fruits n = 16; vegetables n = 43) and (2)

produce that was grown in soil not believed to have been irrigated with contaminated well water

(fruits n = 1; vegetables n = 6). A statistical comparison of the data for the two categories of

vegetables indicated that irri gation with contaminated well water did not cause a significant

increase in contaminant levels (Weston 1998) . The following trends were also noted:

 The concentrations of most metals were high er in root vegetables than other types of

vegetables and fruit.

 Concentrations were much lower in peeled tu rnips than in whole turnips, suggesting that

most of the contamination was on or in the su rface layer.

 There was high variability both within and between the different types of produce.

 Concentration values were below the limit of detection for many of the samples.

E. Ambient Air

ATSDR reviewed ambient air monitoring data and air sampling data collected from the

following two sources:

 Cotter Mill has operated an ambient air mon itoring program to characterize air quality

impacts of radioactive particulates and ra don for more than 20 years. ATSDR accessed

summaries of the monitoring data from Cotter Mill’s annual Environmental and

Occupational Performance Reports, which ar e posted to the CDPHE’s web site; and

 The state of Colorado operated three particulate monitoring stations in Fremont County,

one each in Lincoln Park, Cañon City, and Flor ence. The station in Cañon City continues

to operate today. ATSDR downloaded measured concentrations of particulate matter, and

some chemical constituents of particulate matter, from EPA’s Air Quality System (AQS)

database—a publicly accessibl e online clearinghouse of am bient air monitoring data.

Some of the measurements collected by these monitors date back 40 years.

Historically, Cotter Mill had two general types of air emission sources: ground-level fugitive

emissions (e.g., wind-blown dust) that would be e xpected to have greate st air quality impacts

nearest the source; and elevated point sources (e.g., stacks) that have the potential for having

peak ground-level impacts at downwind locations. With the facility curre ntly in “stand down”

40Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### status, facility emissions are now predominantly fugitive and their air qua lity impacts should be

adequately characterized by the perimeter monitoring stations.

1. Nature and extent of air contamination

ATSDR compiled and evaluated ambient air mon itoring data to assess potential air quality

impacts from Cotter Mill’s past and ongoing operati ons. As will be discussed later, ambient air

concentrations of some substan ces changed considerably from one year to the next—in some

cases, annual average concentratio ns vary by more than a factor of 250 over the period of record.

These substantial changes in measured air contamin ation levels can sometimes be traced back to

site-specific activities.

To provide background information and context for the air qualit y trends documented later in

this report, the following list identifies key milestones over the history of Cotter Mill’s

operations. The timeline is not intended to be a comprehensive listing of s ite-specific events, but

rather focuses on events and activities expected to be associated with not able changes in the

facility’s air emissions

.

 1958: Cotter Corporation begins its uranium milling operations at the Cotter Mill site

 1979: Continuous operations cease, but intermittent operations continue

 1981-1983: Cotter excavates 2,500,000 c ubic yards of contaminated tailings from unlined

holding ponds and places the material in a newly constructed, lined surface impoundment

 1987: Cotter suspends its primary milling opera tions and only limited and intermittent ore

processing occurs for the next 12 years

 1993-1999: Cotter excavates 9,000 cubic yards of contaminated tailings, soil, and

sediment from 1.25 miles of Sa nd Creek near the facility

 1999: Cotter excavates 100,000 cubic yards of c ontaminated soil in “near surface soils”

from the on-site Old Pond Area and places this material into the lined, surface

impoundment

 1999: Milling operations using a di fferent production process begin

 2005: Cotter ceases its routine operations and enters “stand down” status; site

remediation activities continue ; stack emissions from most sources continue into 2006,

after which the main operational stack is for the laboratory baghouse

 2009: Cotter submits letter to CDPHE announcing its intent to refurbish the mill, rather

than decommission it

The following sections summarize the data and air quality trends for particulate matter, selected

particle-bound radionuclides, ra don gas and gamma radiation.

41Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### a) Ambient Air Monitoring for Radioactive Substances

The Cotter Mill monitoring network is operated by Cotter Mill in accordance with guidelines and

requirements set forth by the U.S. Nucl ear Regulatory Commission (USNRC 1980) and the

Radioactive Materials License established be tween Cotter Mill and the state of Colorado

[CDPHE 2009]. The purpose of the network is to characterize the extent to which Cotter Mill’s

operations affect off-site air quality.

Cotter Mill’s ambient air monitoring network ha s been operating from 1979 to the present, but

the number of monitoring stations included in the network has changed over time. In 1979, four

stations were fully operationa l; this increased to seven by 1981 and to ten by 1999. These ten

monitoring stations continue to operate today. Ea ch station is equipped with the same monitoring

equipment: an environmental air sampler used to collect particulates for analysis of particlebound radionuclides; a radon track etch meas urement device; and an environmental

thermoluminescent dosimeter (TLD) for measuri ng gamma exposure. The height of the sampling

inlet probes was not specified in the reports th at ATSDR reviewed to prepare this health

assessment. Table 51 in Appendix A identifies the monitoring stations and their periods of

operation. Figure 23 in Appendix B shows the approxi mate locations of the monitoring stations.

For purposes of this evaluation, ATSDR has classified the ten monitoring stat ions as being either

“perimeter” or “off-site.” The five “perimeter ” monitoring stations are located along or just

within Cotter Mill’s property line; and the five “off-site” monitoring stations are located off-site,

anywhere from 0.5 mile to 4 miles fr om the Cotter Mill property line.

(1) Particulate Matter

At each of the 10 monitoring stations described above, Cotter Mill operates a high-volume total

suspended particulate (TSP) sampling device. Fo r each sampling period, the devices are loaded

with glass fiber filters that collect airborne particulates as ambient air passes through the

sampling apparatus. The TSP sampling devices co llect 1-week integrated samples; when the

sampling period ends, field personnel remove f ilters, record observations on chain-of-custody

forms, and store filters for s ubsequent laboratory analysis.

Cotter prepares annual summary reports for its environmental monitoring network, and those

reports document monthly average TSP concentr ations measured at each station. ATSDR had

access to the summary reports for 2006, 2007, and 2008. TSP data from earlier years can be

accessed through data reports that CDPHE has on compact disk. Over the last three years, annual

average TSP concentrations were consistently hi gher in the more populated areas (Lincoln Park

and Cañon City) than at the perimeter monitori ng stations. In 2008, for instance, the annual

average TSP levels at Lincoln Park and Cañon City were 29.9 μg/m 3 

### and 26.5 μg/m 3



### , respectively; in contrast, annual average concentra tions at the five perimeter monitoring stations

ranged from 15.5 μg/m 3 

### to 21.4 μg/m 3



### .

Although quantitative quality control information was not available when summarizing Cotter’s

TSP data, these measurements can be compared to CDPHE’s PM 10 

### monitoring results in Cañon

City during the same time frame. From 2006 to 2008, the annual average TSP levels measured

by Cotter Mill in Cañon City were 26.6 μg/m 3 

### , 26.3 μg/m 3 

### , and 26.5 μg/m 3 

### , respectively; the

annual average PM 10 

### levels measured by CDPHE in Cañon City during these same years were

42Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 16.5 μg/m 3 

### , 16.4 μg/m 3 

### , and 15.0 μg/m 3 

### . The difference between the TSP and PM 10 

### annual

average concentrations in Cañon City are within the expected range and direction (i.e., TSP

levels exceeding PM 10 

### levels), which gives some assurance in the quality of the underlying data

sets.

(2) Particle-Bound Radionuclides

Weekly particulate filters collect ed at the 10 stations mentioned in the previous section are not

only weighed for mass loading but are also analyzed at Cotter Mill’s analytical laboratory for

concentrations of five radionucli des, identified below. All labo ratory analyses are conducted

according to methodologies approved by CDPHE.

Field sampling and laboratory analyses for pa rticle-bound radionuclides are conducted according

to specifications outlined in Cotter Mill’s Quality Assurance Program Plan (QAPP). This

document is revised periodically and submitted to CDPHE for review. The QAPP outlines many

quality control and quality assurance procedures implemented to ensure that the network’s

measurements are of a known and high qualit y. Examples of specific procedures followed

include: routine collection and analysis of blank samples to ensure sampling media and

laboratory equipment are not contaminated; quart erly calibration of flow rates for the “high

volume” samplers; audit of sampler flow rates using special equipment; collection of duplicate

samples that are analyzed in replicate to quantif y measurement precision; and participation in a

“laboratory exchange program” through which a s ubset of environmental samples (mostly water

samples, by all appearances) are split and sent to Cotter Mill’s laborat ory and two commercial

laboratories for analyses. While th ese and other quality control procedures give some assurance

that samples are collected and analyzed with fine attention to data quality, the reports available to

ATSDR during this review gene rally did not present the actual data quality metrics (e.g., the

relative percent difference in dupl icate samples or for inter-laboratory audits, contamination

levels found in blanks) for th e particle-bound radionuclides.

The key findings from the monitoring program fo r the five radionuclides measured are below.

For each substance, a section compares the meas ured concentrations to regulatory limits or

health-based comparison values, comments on tempor al and spatial variati ons, and then presents

a brief summary.

 Natural uranium ( nat 

### U). Table 52 in Appendix A presents the history of annual average

nat 

### U concentrations measured in Cotter Mill’s monitoring network. The shaded cells in

the table are the highest annual av erage concentration for the year.

o Screening. Cotter Mill compares meas ured concentrations of nat 

### U to an “effluent

concentration” (9.0 x 10 -14 

### μCi/ml), which is defined (10 CFR 20, Appendix B) as

the radionuclide concentration which, if i nhaled continuously over the course of a

year, would produce a total effective dose equivalent of 50 mrem. None of the

annual average concentrations in Tabl e 52 exceed this derived concentration

guide. The highest annual average concentr ation over the period of record (2.5 x

10 -14 

### μCi/ml at a perimeter monitoring st ation in 1982) is 3.6 times below this

screening value. The highest annual average in 2008 (4.4 x 10 -16 

### μCi/ml at a

43Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### perimeter monitoring station) was appr oximately 200 times below the screening

value, and larger margins are observed for the off-site monitoring stations.

o Spatial and temporal variations. Generally, the highest annual average

concentrations of nat 

### U were observed at perimeter m onitoring stations, with lower

levels observed at the off-site stations . During most years, the annual average

values did not vary considerably (by more than an order of magnitude) across all

of the stations. As an ex ception, the 1982 annual average nat 

### U concentration

observed at the west boundary monitoring station was roughly 50 times greater

than the annual averages observed at the other monitoring stations during the

same year; this “spike” at one station during one year was most likely caused by

air emissions associated with an on-site tailings excavation project. As another

exception, in several years between 1998 and 2006, annual average nat 

### U

concentrations at the mill entrance road monitoring station were more than an

order of magnitude higher than those reco rded at all other stations, which most

likely reflects contributions from clean-up of the site entry ro ad and delivery of

ores (which mostly ended in 2006). As noted above, the highest annual average

concentration of nat 

### U was observed in 1982, and more recent (2004-2008) annual

average levels are considerably lower.

o Summary. Every annual averag e concentration of nat 

### U recorded to date has been

lower than Cotter Mill’s health-based regul atory limit. In the last five years, the

annual average concentrations at every st ation have been at least 20 times below

this limit. It seems unlikely that air emi ssions from the mill would lead to an offsite “hot spot” of nat 

### U concentrations that could be considerably higher than the

levels measured by the monitoring network.

 Thorium-230 ( 230 

### Th). Table 53 in Appendix A presents the history of annual average

230 

### Th concentrations measured in Cotter Mill’ s monitoring network. The shaded cells in

the table are the highest annual av erage concentration for the year.

o Screening. Cotter Mill compares measured concentrations of 230 

### Th to an “effluent

concentration” (2.0 x 10 -14 

### μCi/ml), which is defined (10 CFR 20, Appendix B) as

the radionuclide concentration which, if i nhaled continuously over the course of a

year, would produce a total effective dose equivalent of 50 mrem. The annual

average concentration at the west boundary monitori ng station exceeded this

value in 1981 and 1982, as did the annual average concentration in 1981 at the

east boundary monitoring station. The hi ghest annual average concentration

recorded by this network (9.0 x 10 -14 

### μCi/ml at the west boundary in 1982) was

4.5 times higher than the derived concentr ation guide. Concentrations decreased

over the years, and the highest annual average in 2008 (7.2 x 10 -16 

### μCi/ml at a

perimeter monitoring station) was a factor of 28 times lower than the screening

value, and larger margins are observe d for the off-site monitoring stations.

o Spatial and temporal variations. Without exception, the highest annual average

concentrations of 230 

### Th were observed at perimeter monitoring stations, with

44Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### considerably lower levels observed at the off-site stations—a spatial trend

suggesting that Cotter Mill’s emissions very likely account for a considerable

portion of the measured levels. As with natural uranium, the 230 

### Th concentrations

exhibited a notable “spike” in 1981-1982, wh en 2.5 million cubic yards of on-site

tailings were excavated from the unlined ponds. As an illustration of this effect,

the highest annual average concentration in 1981 (3.0 x 10 -14 

### μCi/ml at a

perimeter monitoring station) was ne arly 370 times higher than the annual

average concentration measured in Cañon City. Moreover, the highest

concentrations were observed at the m onitoring station closest to, and downwind

from, the excavation activity. Average concentrations of 230 

### Th decreased

markedly after the 1981-1982 peak: the mo st recent (2004-2008) annual average

concentrations at perimeter stations are al l at least 20 times lower than the highest

levels from 1981-1982.

o Summary. In 1981 and 1982, annual aver age concentrations of 230 

### Th at two

perimeter monitoring stations exceeded Cotter Mill’s health-based regulatory

limit; however, for every other calendar year, every station’s annual average

concentration was lower than this limit. In the last fi ve years, the annual average

concentrations at every st ation were between six and 30 times below this limit.

For the off-site monitoring stations, how ever, all annual average concentrations

during this 5-year time frame were at l east a factor of 40 below Cotter Mill’s

health-based regulatory limit.

 Thorium-232 ( 232 

### Th). Table 54 in Appendix A presents the history of annual average

232 

### Th concentrations measured in Cotter Mi ll’s monitoring network. Laboratory analyses

for this radionuclide first began in 2001. The shaded cells in the table are the highest

annual average concentration for the year.

o Screening. Cotter Mill compares meas ured concentrations of 232 

### Th to an “effluent

concentration” (4.0 x 10 -15 

### μCi/ml), which is defined (10 CFR 20, Appendix B) as

the radionuclide concentration which, if i nhaled continuously over the course of a

year, would produce a total effective dose equivalent of 50 mrem. None of the

annual average concentrations in Tabl e 54 exceed this derived concentration

guide. In 2008, the highest annual average concentration (3.1 x 10 -17 

### μCi/ml in

Lincoln Park) was a factor of 128 lower than the screening value.

o Spatial and temporal variations. Unlike nat 

### U and 230 

### Th, for which measured

concentrations were consistently (if not always) highest at perimeter monitoring

stations, the highest annual average concentrations of 232 

### Th have always been

observed at off-site mon itoring stations, most commonly at the Lincoln Park

monitoring station. Moreover, of all the radionuclides measured, annual average

concentrations of 232 

### Th exhibited the least variability from station to station. For

any given year between 2001 and 2008, annua l average concentrations at the ten

monitoring stations fell within a factor of three of each other. The annual average

concentrations did not exhibit considerable variability from one year to the next.

45Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### o Summary. Over the last five years, an nual average concentrations of 232 

### Th at

every monitoring station were more than 60 times lower than Cotter Mill’s healthbased regulatory limit. The spatial variations in 232 

### Th concentrations have been

limited, suggesting that air emissions from Cotter Mill may be relatively

insignificant for this radionuclide.

 Radium-226 ( 226 

### Ra). Table 55 in Appendix A presents the history of annual average

226 

### Ra concentrations measured in Cotter Mill’ s monitoring network. The shaded cells in

the table are the highest annual av erage concentration for the year.

o Screening. Cotter Mill compares measured concentrations of 226 

### Ra to an “effluent

concentration” (9.0 x 10 -13 

### μCi/ml), which is defined (10 CFR 20, Appendix B) as

the radionuclide concentration which, if i nhaled continuously over the course of a

year, would produce a total effective dose equivalent of 50 mrem. None of the

annual average concentrations in Tabl e 55 exceed this derived concentration

guide. In 2008, the highest annual average concentration (7.9 x 10 -16 

### μCi/ml at a

perimeter monitoring station) was three orders of magnitude lower than the

screening value.

o Spatial and temporal variations. In almost every year between 1979 and 2008, the

highest annual average concentrations of 226 

### Ra were measured at perimeter

monitoring stations, and primarily at th e west boundary and mill entrance road

locations. For most years, the highest annual average value at the facility’s

perimeter was usually between one and two orders of magnitude greater than the

lowest annual average concentration at o ff-site locations—a pattern that points to

facility emissions as a likely source fo r contributing to at least part of the

measured concentrations. At the four peri meter stations with the longest period of

record, the highest annual av erage concentrations occu rred prior to 1985, and the

current (2008) levels at these stations are between 10 and 100 times lower than

those peaks.

o Summary. The spatial variations in 226 

### Ra concentrations sugges t that Cotter Mill’s

emissions contribute to the measured leve ls. However, over the last five years,

annual average concentrations of 226 

### Ra at every monitoring station were more

than 390 times lower than Cotter Mill ’s health-based regulatory limit.

 Lead-210 ( 210 

### Pb). Table 56 in Appendix A presents the history of annual average 210 

### Pb

concentrations measured in Cotter Mill’s m onitoring network. The shaded cells in the

table are the highest annual aver age concentration for the year.

o Screening. Cotter Mill compares measured concentrations of 210 

### Pb to an “effluent

concentration” (6.0 x 10 -13 

### μCi/ml), which is defined (10 CFR 20, Appendix B) as

the radionuclide concentration which, if i nhaled continuously over the course of a

year, would produce a total effective dose equivalent of 50 mrem. None of the

annual average concentrations in Tabl e 56 exceed this derived concentration

guide. In 2008, the highest annual average concentration (1.9 x 10 -14 

### μCi/ml at a

46Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### perimeter monitoring station) was more than a factor of 30 lower than the

screening value.

o Spatial and temporal variations. The main distinguishing feature of the 210 

### Pb

monitoring data (when compared to data for the other radionuclides) is the low

variability, both spatially and te mporally. Since 1983, annual average

concentrations across the ten monitoring sta tions tended to fall within a factor of

two; and year-to-year variability was of a comparable magnitude. This lack of

variability points to a “background effect” (i.e., the measured concentrations

likely are not the result of Cotter Mill’s emissions, but reflect typical atmospheric

levels for this part of the country). In 1981-1982, annual average concentrations at

a perimeter monitoring station were sli ghtly higher than what was routinely

measured at all other locati ons and years; and these slightly elevated levels likely

reflected air quality impacts from the ex cavation of the unlined holding ponds.

o Summary. Of all the radionuclides considered, 210 

### Pb showed the least variability

in annual average concentrations, suggesti ng that the monitoring data characterize

background levels and not a site-specific contribution. From 1983 to the present,

annual average concentrations during ev ery year and at every station were

generally at least 20 times below Cotter Mill’s health-based regulatory limit.

With one exception, the five radioactive substa nces measured by Cotter Mill’s network were

below their corresponding health-based regulatory limits at a ll 10 monitoring stations and for the

entire 30 years of record. As the exception, annual average 230 

### Th concentrations exceeded healthbased regulatory limits during a tailing pond excavation project, but this was limited to a short

time frame (1981-1982) and the immediate proximity of the facility (two fenceline monitoring

locations). The spike in measured concentratio ns during this time frame was far less pronounced

(if not completely imperceptible) at monitoring stations in Linc oln Park or Cañon City. Another

spatial variation linked to s ite activities is the relativel y elevated readings (e.g., for nat 

### U) observed

at the “mill entrance road” monitoring station between roughly 1997 and 2006.

Over the last five years, annual average concen trations of every radionuc lide were at least 20

times lower than health-based screening limits at the five off-site monitoring stations. This large

margin provides some assurance that the monitori ng network has adequate coverage in terms of

monitors—it is quite possible that annual average ambient air concen trations of radionuclides at

some un-monitored off-site locations exceed what has been measured to date, but it is far less

likely that the network is failing to capture a “hot spot” with c oncentrations more than 20 times

higher than the levels that are currently measured.

b) Radon Gas

Cotter measures radon gas concentrations at the same ten monitoring stations where particlebound radionuclides are sampled. The annual envi ronmental monitoring reports provide very

limited information on the sampling methodology, ot her than noting that the detectors are

apparently exposed to ambient air for a calendar quarter and then retrieved for laboratory

analysis. Recent data summary re ports suggest that a new samp ling and analytical method was

implemented in the second quarter of 2002. This new method outputs combined 220 

### Rn (from

47Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### natural thorium) and 222 

### Rn (from natural uraniu m). However, the report does not describe what

the previous sampling and an alytical method measured.

According to Cotter’s radon sampling procedur es (Cotter 2004b), the sampling devices are

“Landauer Type DRNF Radon Detectors.” The repor ts provided to ATSDR suggest that various

quality control measures have been implemented for this sampling (e.g., collection and analysis

of duplicate samples to characterize precision) , but they do not document quantitative data

quality metrics. The method detection limit for the combined 220 

### Rn/ 222 

### Rn measurement is 70

pCi/m 3 

### (Cotter 2004b). This appears to offer adequate measurement sensitivity, because most

quarterly average concentrations measured sinc e this method was implemented are at least an

order of magnitude greater than the detection limit.

Table 57 presents the annual average 220 

### Rn/ 222 

### Rn concentrations that Cotter has measured from

2002 to the present. Data are not presented for earlier years (1979 to 2001), as they may not be

directly comparable due to the use of differe nt measurement technologies. Cotter has recently

concluded that its radon monitoring data “demons trate slightly elevated readings at boundary

locations [when compared to] readings in resi dential areas at background levels” (Cotter 2008b).

This statement seems to be supported, in a gene ral sense, by the monitoring results, though the

difference between the perimeter and the off-site c oncentrations is much lower in certain years,

particularly in 2008.

The approach used for screening the 220 

### Rn/ 222 

### Rn concentrations differs from that used for other

radionuclides. Cotter screens the 220 

### Rn/ 222 

### Rn using an approach approved by CDPHE. In this

approach, Cotter derives an “effective effluent li mit” based on a baseline regulatory limit, an

equilibration factor for the measurements, a nd average background concentrations that are

calculated semi-annually. The details of this deri vation are documented in a letter that CDPHE

sent to Cotter in June, 2004. The net effect of this calculation approach is that the “effective

effluent limit” (i.e., the concentration used for screening purposes) can vary across the

monitoring stations and years. To illustrate this point, between 2006 and 2008, the “effective

effluent limit” of 220 

### Rn/ 222 

### Rn concentrations rang ed from 1,290 to 1,981 pCi/m 3 

### , depending on

the magnitude of the background co ncentrations at the time. Duri ng this time frame, measured

concentrations at perimeter monitoring stations r eached as high as 85% of the “effective effluent

limit.”

c) Gamma Radiation

Cotter measures gamma radiation levels at the same ten monitoring sta tions where particlebound radionuclides are sampled. Measurements ar e made using thermoluminescent dosimeters

(TLDs) that are exposed for 3- month periods before being sent off-site for analysis. Every

calendar quarter, an additional dup licate TLD is deployed to at least one monitoring station to

assess measurement precision, and a control TLD is placed in a lead-shielded box at another

location to serve as a “blank” sample. However, the site reports provided to ATSDR did not

contain any quantitative metrics of data quality (e.g., relative per cent difference in co-located

samples).

Table 58 presents annual average gamma ra diation exposure rates between 1979 and 2008, by

monitoring station; these annual averages were ca lculated from the quarterly TLD measurements

48Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### from each calendar year. For every year on recor d, the highest annual average exposure rate was

observed at one of the perimeter monitoring st ations. Since Cotter installed the monitoring

station at the mill’s entrance road in 1994, this station has recorded the highest annual average

exposure rates every year through the present. Th e relatively high readings at this location are

believed to result primarily from past spillage or incoming materials entering the facility (Cotter

2008b). Under oversight from CDPHE, Cotter re moved contamination al ongside the entrance

road in 2006 and 2007, with exposur e rates decreasing thereafter.

Cotter’s monitoring reports do not include heal th-based screening evaluations for these

measurements, but they do acknowle dge that the exposure rates nearthe facility perimeter (and

particularly along the entrance road) exceed ba ckground levels. Specifically, the reports assume

that the Cañon City station’s measurements refl ect “background” contributi ons from all external

sources. The report indicates that the reported background level at this station (10.2 μR/hr) is

equivalent to a dose of 89 mrem/year.

d) Ambient Air Monitoring fo r non-Radioactive Substances

To prepare this summary, ATSDR accessed all ambi ent air monitoring data that the state of

Colorado collected in Fremont County and report ed to EPA’s Air Quality System (AQS), an

online clearinghouse of monitoring da ta that states collect to a ssess compliance with federal air

quality standards. The AQS database included m onitoring results for three locations in Fremont

County: one in Cañon City, one in Lincoln Park, and one in Florence. This section summarizes

only those data collected in Cañon City and in Lincoln Park given their closer proximity to

Cotter Mill. However, the monitoring summari zed in this section was not conducted to

characterize air quality impacts associated with Cotter Mill’s emissions; the measured

concentrations at these locations likely reflect contributions from many different local emission

sources (e.g., mobile sources, wind-blown dust, wood-burning stoves). Th e AQS database does

not specify quality control parameters for the monitoring results; however, state agencies that

submit data to AQS are supposed to thoroughly valid ate measured concentrations before entering

them into the database.

(1) Particulate Matter (TSP, PM 10 

### , and PM 2.5 

### )

The state-operated Cañon City and Lincoln Park monitoring stations measured three different

size fractions of particulate matter between 1969 a nd the present. Following standard practice, all

three size fractions were measured in 24-hour av erage integrated samples that were typically

collected once every 6 days, though more frequent monitoring occurred during some years.

Measurements were collected usi ng either standard technologies (e.g., high-volume samplers for

TSP and PM 10 

### ) or EPA-approved Federal Reference Me thod devices. A brie f summary of the

measurements follows:

 TSP measurements. From 1969 through 1987, high-volume sampling devices were used

to measure TSP. Table 59 in Appendix A pr esents the maximum and annual average TSP

concentrations measured by the two monitoring stations over the period of record.

Annual average TSP in Cañon City did not change considerably from 1969-1987. In

Lincoln Park, only two calendar years have complete data sets; the annual average

concentration in 1982 was below the range of annual averages observed at Cañon City.

49Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### The fact that TSP levels were lower in Li ncoln Park than in Ca ñon City suggests that

Cotter Mill’s emissions are not the primary contribution to TSP levels in the area.

 PM 10 

### measurements. The state of Colorado began monitoring PM 10 

### in Cañon City in

1987 and continues this monitoring today. The monitoring station was originally located

at the courthouse in Cañon C ity, but the state moved the mo nitoring equipment in 1987 to

a less obstructed site at city hall. Annual average PM 10 

### concentrations throughout the

period of record range from 15 to 23 μg/m 3 

### , well below EPA’s former National Ambient

Air Quality Standard for annual average levels (50 μg/m 3 

### ). Between 1987 and 2009, only

one measured 24-hour average concentrati on exceeded EPA’s current health-based

standard; that occurred in 1988 and likely reflected contri butions from many different

local sources and should not be attributed solely to Cotter Mill’s emissions.

 PM 2.5 

### measurements. In 1991 and 1992, the state conducted PM 2.5 

### monitoring at its

Cañon City station. All measured 24-hour average concentrations and both annual

average concentrations were lower than th e health-based standards that EPA would

develop later in the 1990s. This monitori ng occurred before EPA designated Federal

Reference Methods for PM 2.5 

### measurement devices.

(2) Constituents of Particulate Matter

Between 1978 and 1987, the state of Colorado analyzed some of the TSP filters collected in

Cañon City and Lincoln Park for chemical constitu ents. This included analyses for metals (iron,

lead, manganese, and zinc) and ions (nitrate and sulfate). Table 60 summarizes these

measurements by presenting the highest 24-hour average concentration and the highest annual

average concentration fo r the period of record.

50Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## V. PUBLIC HEALTH EVALUATION

A. Introduction

This section of the public health assessment evaluates the health e ffects that could possibly result

from exposures to site-related contaminants at or near the Co tter Mill site. For a public health

hazard to exist, people must contact contam ination at levels high enough and for long enough

time to affect their health. The environmental da ta and conditions at the site revealed five

completed exposure pathways:

1. Exposure to site-related contaminants in groundwater in Lincoln Park.

2. Contact with site-related contaminants in so il adjacent to the Cotter Mill and in Lincoln

Park.

3. Contact with site-related contaminants in surface water downstream from the Cotter Mill.

4. Exposure from eating produce locally grown in Lincoln Park

5. Exposure to ambient air near the Cotter Mill facility

B. How Health Effects are Evaluated

The potential health effects associated with comp leted exposure pathways ( listed above) will be

evaluated in this section. For chemicals found to exceed comparison values, ATSDR calculated

exposure doses and estimated non-can cer and cancer risks, where applicable. The calculations

estimate the amount of the chemical to which a person may have been exposed. Calculated

exposure doses are then compared to the available health guide lines to determine whether the

potential exists for adverse non-cancer health effect s. In the event that calculated exposure doses

exceed established health guidelines (e.g., ATSDR’s Minimal Risk Levels or EPA’s Reference

Doses), an in-depth toxicological evaluation is necessary to determine the likelihood of harmful

health effects. ATSDR also may compare the

estimated amount of exposure directly to

human and animal studi es, which are reported

in ATSDR's chemical-specific toxicological

profiles. Not only do the toxicological

profiles provide health information,

they also provide information about

environmental transport, human exposure,

and regulatory status.

A detailed explanation of ATSDR’s evaluation

process for determining cancer and non-cancer

health effects is contai ned in Appendix C of

this document. The equations to calculate

exposure doses, the exposure scenarios,

and the exposure assumptions used to

estimate exposures at this site are also

in Appendix C. ATSDR’s Minimal Risk Level (MRL), which is

derived from human and animal studies, is an

estimate of daily exposure to a contaminant

below which non-cancer health effects are

unlikely to occur.

EPA's Reference Dose An estimate (with

uncertainty spanning perhaps an order of

magnitude) of a daily oral exposure to the

human population (including sensitive

subgroups) that is likely to be without an

appreciable risk of deleterious effects during a

lifetime. It can be derived from a NOAEL,

LOAEL, or benchmark dose, with uncertainty

factors generally applied to reflect limitations of

the data used. Generally used in EPA's

noncancer health assessments.

51Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### C. Groundwater Pathway: Private wells used for personal consumption

As discussed above, the data from the 1989 Lincoln Park Water Use Survey survey indicated

approximately 7 wells are used for personal cons umption; sampling data for 6 of the 7 wells

were available to ATSDR for evaluation. Sample s were collected intermittently from 1984 to

2007.

Although most residents in Lincol n Park currently use municipal water for drinking purposes, the

survey reveals that residents at 7 locations still use th eir private wells for drinking purposes. It is

not verified whether residents who reported using their well wate r for personal consumption also

use their well water for other household purpos es, such as bathing and showering. Some

residents report that they and others used their private wells for personal consumption and other

household uses in the past (befor e the installation of the municipal water line). Therefore, it is

reasonable to assume that many more people obtain ed their drinking water from private wells in

the past, and that some people are continuing to use their private wells for drinking, and possibly,

household purposes.

Very little quantitative information is known about what levels of contamination residents may

have been exposed to in the past. However, AT SDR attempted to address this issue by assuming

that the average resident would have been expos ed to the average chemical concentration (i.e.,

temporal average per well) detected in the 6 private wells for which we have sampling data.

There is some uncertainty in using this estimate because some people may have been exposed to

more, and some to less, than the estimated amou nt. To capture the resident who may have been

more highly exposed (or a worst case scenar io), ATSDR used the average chemical

concentration from the single private well that consistently contained the highest chemical

concentrations (Well 189). ATSDR assumed that a dults and children drank the water from this

well for 350 days per year for 30 years (adu lts) and 6 years (child ren), respectively.

Molybdenum was the only chemical in private we lls that had an average detected level (0.082

mg/L) that exceeded its comparison value (0.05 mg/L). The average level of molybdenum in

Well 189 (0.16 mg/L) also exceeded the comparis on value for molybdenum in drinking water.

Therefore, molybdenum was retained as a chem ical of concern and evaluated for possible

adverse health effects. The maximum detected level of uranium (0.067 mg/L), but not the

average detected level (0.028 mg/L), also ex ceeded the comparison value of 0.03 mg/L for

uranium. Additionally, the average detected le vel of uranium in Well 189 (0.048 mg/L) exceeded

the comparison value for uranium. Therefore, ATSDR evaluated uranium more closely for

potential adverse health effects. Table 7 belo w summarizes the estimated child and adult doses

for molybdenum and uranium that guide the health discussion below. (See Table C1 in Appendix

C for a detailed discussion of how these values were derived.)

52Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 7. Estimated Child and Adult Doses for Molybdenum and Uranium

in Drinking Water

Chemical Exposure

Group Adult

Estimated Dose

(mg/kg/day) Child

Estimated Dose

(mg/kg/day) Health

Guideline

(mg/kg/day)

Molybdenum Well 189

(high

exposures) 0.004 0.010

0.005

Chronic Oral

RfD All wells

(average

exposures) 0.002 0.005

Uranium Well 189

(high

exposures) 0.001 0.003

0.002

Intermediate

Oral MRL All Wells

(average

exposures) 0.0008 0.002



### 1. Molybdenum

Molybdenum is a naturally occurring element found in various ores. Molybdenum is also

considered an essential dietary nutrient in humans and animals. Foods such as legumes, leafy

vegetables, nuts and cereals tend to be higher in molybdenum than meats, fruits, and root and

stem vegetables [WHO 2003]. The Food and Nutriti on Board (FNB) of the Institute of Medicine

has determined the Tolera ble Upper Intake Level 12 

### (UL) for molybdenum in children and adults

[FNB 2001] as follows:

 children 1 to 3 years of age - 0.3 mg/kg/day;

 children 4 to 8 years of age - 0.6 mg/kg/day;

 children 9 to 13 years of age - 1.1 mg/kg/day;

 adolescents 14 to 18 years of ag e - 1.7 mg/kg/day; and

 adults - 2.0 mg/kg/day.

a) Health Evaluation of Molybdenum

Drinking water from a private well contaminated w ith molybdenum would result in an estimated

dose of 0.002 mg/kg/day for an average adult and 0.005 mg/kg/day for an average child. The

adult dose is lower than the oral RfD of 0.005 mg/kg/day for molybdenum. The estimated child

dose is equal to the oral RfD (0.005 mg/kg/day) for molybdenum. Therefore, adverse health

12 UL = maximum level of daily nutrient intake that is lik ely to pose no risk of ad verse health effects in all

individuals. The UL represents the total intake from food, water, and supplements.

53Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### effects are not expected for the average a dult or child who drank from a private well

contaminated with molybdenum.

Adults who may have had high exposures, such as those similar to Well 189, have an estimated

dose of 0.004 mg/kg/day, and childre n who may have had high expos ures have an estimated dose

of 0.010 mg/kg/day. The adult high dose is less th an the oral RfD for molybdenum. However, the

estimated child high exposure dose is 2 times gr eater than the oral Rf D of 0.005 mg/kg/day for

molybdenum. Because the estimated exposure dose for children exceeds the long-term health

guidelines for molybdenum, the possibility of health consequences from this exposure was

evaluated further.

To further evaluate the possibility of adverse h ealth effects, ATSDR divides the lowest observed

adverse effect level (LOAEL) and/or the no observed adverse effect level (NOAEL) by the sitespecific exposure doses. Interpretation of the re sulting value is subjective and depends on a host

of toxicological factors. Furthe r evaluation consists of a careful comparison of site-specific

exposure doses and circumstances with the epidemiologic and experimental data on the

chemical. The purpose of the comparison is to ev aluate how close the estimated exposure doses

are to doses that cause health effects in humans or animals.

The oral RfD for molybdenum is based on a hu man epidemiological study that found a LOAEL

of 0.14 mg/kg/day for increased serum uric acid levels and prevalence of gout-like condition in

Armenian villagers [Koval’skiy 1961]. A higher incidence (18-31%) of a gout-like disease was

associated with high intake of molybdenum ( 10-15 mg/day) from soil an d plants. The gout-like

condition was characterized by pai n, swelling, inflammation and deform ities of the joints, and, in

all cases, an increase in the ur ic acid content of the blood. In a nu mber of cases, illnesses of the

GI tract, liver, and kidneys accompanied the cond ition [EPA IRIS]. In deriving the oral RfD, an

uncertainty factor of 3 was used for protection of sensitive human populati ons and a factor of 10

was used for the use of a LOAEL instead of a NOAEL for a long-term study in a human

population. The estimated child high dose (0.010 mg/kg/day) for molybdenum at the Cotter

Mill/Lincoln Park site is 14 times lower than the LOAEL from this study. There was no NOAEL

determination for molybde num from this study.

Molybdenum is known to interfere with coppe r metabolism in ruminant animals (grazing

animals that “chew their cud,” such as sheep or cows); the resulting copper deficiency is reported

to cause the animal’s hair/wool to turn white [FNB 2001]. This is a problem with ruminant

animals in particular because high dietary mo lybdenum reacts with moderate to high dietary

sulfur in the rumen (the first stomach) to fo rm thiomolybdates. These compounds greatly reduce

copper absorption, and certain thio molybdate species can be absorb ed and interfere systemically

with copper metabolism [Spear 2003]. This inte raction between thiomolybdates and copper is

not expected to occur to a significant de gree in humans [Turnlund 2002]. Although the exact

effect of molybdenum intake on copper status in humans remains to be clearly established,

individuals who do not take in e nough dietary copper or cannot pro cess it correctly could be at

increased risk of molybde num toxicity [FNB 2001].

In conclusion, children who drink water containing high concentra tions of molybdenum could be

at increased risk of adverse health effects su ch as gout-like symptoms. However, molybdenum is

not stored at high levels in the body, so it is unl ikely that children will suffer long-term health

54Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### effects once the exposure is stopped [FNB 2001]. In healthy people, excess molybdenum is not

associated with adverse health outcomes. Ho wever, individuals who do not take in enough

dietary copper or cannot pr ocess it correctly could be at increased risk for adverse health effects.

The actual risk of adverse health effects occurring depends on the concentration of molybdenum

in the water and how much water is drunk. Theref ore, private wells known to be contaminated

with molybdenum should not be used for drinking purposes.

b) Additional Comments about Moly bdenum in Drinking Water

 ATSDR did not evaluate poten tial exposures to molybdenum that could occur if well

water is used for other household purposes such as showering or bathing. If it is

confirmed that residents are using their wells for other po table purposes, then exposure

levels would increase, as we ll as the likelihood of adverse health effects. However,

exposure to airborne and/or dermal molybdenum is not likely to be a major exposure

pathway because of the physicochemi cal properties of molybdenum.

 The estimated dose for children and adults at this site did not exceed the Tolerable Upper

Intake Level (UL) for molybdenum establishe d by the Institute of Medicine. However,

ATSDR’s evaluation did not consider molybde num intake from other sources, including

food and supplements, which woul d increase total intake.

 Molybdenum is often found naturally in the geology of this region. The wells identified

and sampled as background for the Lincoln Park area contained an average molybdenum

concentration of 0.023 mg/L. This concentration is lower th an the average of 0.082 mg/L

found in private wells used for personal c onsumption. The maximum concentration of

molybdenum in a background well (0.3 mg/L) was about the same as that in a private

well (0.28 mg/L) used for personal consumption.

 Overall molybdenum levels in groundwater decreased over time. Molybdenum levels

measured from 1968 to 2000 show a clear pattern of decrease in molybdenum

concentrations. Therefore, exposures to mo lybdenum in groundwater were likely higher

in the past, and may continue to decrease in the future.

People who currently own private wells are not pr evented from using their private wells for any

purpose. New residents who move to the area may install new wells in the contaminated zone

and use their well for any purpose. Therefore, this exposure pathway will c ontinue to exist as a

potential exposure pathway in the future.

2. Uranium

Throughout the world uranium is a natural and common radioactive element. Uranium is a

silver-white, extremely dense, and weakly radioac tive metal. It is typically extracted from ores

containing less than 1% natural uranium. Natural uranium is a mixture of three isotopes: 238U

(99.2739%), 235U (0.7204%), and 234U (0.0057%). It usually occurs as an inorganic compound

with oxygen, chlorine, or other elements [NHANES 2005]. Rocks, soil, surface and ground

water, air, plants, and animals all contain va rying amounts of uranium. Colorado ranks third,

55Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### behind Wyoming and New Mexico, tied with Ariz ona and Utah, as the state with the most

uranium reserves in the United States [EIA 2001].

a) Health Evaluation of Uranium

Natural uranium is radioactive but poses little radioactive dange r—it releases only small amounts

of radiation that cannot travel far from its source. Moreover, unlike other types of radiation,

alpha radiation released by natural uranium cannot pass through solid object s, such as paper or

human skin. You have to eat, dri nk, or breathe natural uranium in order to be exposed to the

alpha radiation; however, no adverse effects from natural uranium’s radi ation properties have

been observed in humans. The National Academy of Sciences determined that bone sarcoma is

the most likely cancer from oral exposure to uraniu m; its report noted, however, that this cancer

has not been observed in exposed humans and co ncluded that exposure to natural uranium may

have no measurable effect [BEIR IV].

Scientists have seen chemical effects in peopl e who have ingested large amounts of uranium.

Kidney disease has been reported in both human s and animals that were exposed to large

amounts of uranium; however, the available data on soluble (more bioava ilable) and insoluble

uranium compounds are sufficient to conclude that uranium has a low order of metallotoxicity in

humans [Eisenbud and Quigley 1955].

When uranium is ingested most of it leaves the body through the feces and a small portion

(approximately 2% for an adult) will be absorbed into the blood stream through the

gastrointestinal (GI) tr act. Most of the uranium in the blood is excreted from the body through

urine excretion within a few days; however, a sm all amount will be retained in the kidneys, bone,

and soft tissue for as long as several years. The percentage of the uranium retained in the kidneys

over time is different for acute and chronic i ngestion of uranium (as long as the individual

continues to drink the water). When an i ndividual discontinues drinking the uranium

contaminated water, the percenta ge of retention in the kidney decreases similar to an acute

exposure. In the case of chroni c ingestion of drinking water containing uranium, the kidney

retention (or kidney burden) incr eases rapidly in the first two weeks. After approximately 100

days, the amount present in the kidney is approximat ely 5% of the daily intake for an infant and

approximately 3% for all other ages. After 25 years of chronic ingestion, the uranium kidney

burden reaches equilibrium for all age groups at a pproximately 6.6% of the daily intake [Chen et

al 2004].

Nephrotoxicity (kidney toxicity) occurs when th e body is exposed to a drug or toxin such as

uranium that causes temporary or permanent damage to the kidneys. When kidney damage

occurs, blood electrolytes (such as potassium a nd magnesium) and chemical wastes in the blood

(such as creatinine) become elev ated indicating either a temporar y condition or the development

of kidney failure. Creatinine is a chemical wast e molecule that is generated from muscle

metabolism. The kidneys maintain the blood creatin ine in the normal range. Creatinine is a fairly

reliable indicator of kidney f unction. As the kidneys are impair ed, the creatinin e level in the

blood will rise because of the poor clearance by the kidney. If detected early, permanent kidney

problems may be avoided.

56Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Several mechanisms for uranium-induced kidney toxi city have been proposed. In one of these,

uranium accumulates in specialized (e pithelial) cells that enclose th e renal tubule, where it reacts

chemically with ion groups on the inner surface of the tubule. This interferes with ion and

chemical transport across the tubular cells, cau sing cell damage or cell death. Cell division and

regeneration occur in response to cell damage and death, resulti ng in enlargement and decreased

kidney function. Heavy metal ions, such as uranyl ions, may also delay or block the cell division

process, thereby magnifying the effects of cell damage [Legge tt 1989, 1994; ATSDR 1999].

Animal and human studies conducted in 1940s and 1950s provide evidence that humans can

tolerate certain levels of uranium, suffering only minor effects on the kidney [Leggett 1989].

Most of these studies involved i nhalation exposures to uranium; ho wever, the kidney is the target

organ for inhaled as well as ingested uranium. On the basis of this tolerance, the International

Council on Radiologic Protection (ICRP) adopted a maximal permissible concentration of 3 μ g

of uranium per gram of kidne y tissue for occupational exposur e in 1959 [Spoor and Hursh 1973].

This level has often been interpreted as a threshold for chemical toxicity.

More recent papers have been published on effects of uranium at levels below 3 μ g/g, and those

papers have discussed possible mechanisms of uranium toxicity [Diamond 1989; Leggett 1989,

1994; Zhao and Zhao 1990; Morris and Meinhol d 1995]. It is thought that the kidney may

develop an acquired tolerance to uranium after repeated doses; however, this tolerance involves

detectable histological (structu ral) and biochemical changes in the kidney that may result in

chronic damage. Cells of the inner surface of th e tubule that are regenerated in response to

uranium damage are flattened, with fewer energy-producing organelles (mitochondria).

Transport of ions and chemicals across the tubule is also altered in the tubule cells [Leggett

1989, 1994; McDonald-Taylor et al. 1997]. These eff ects may account for the decreased rate of

filtration through the kidney and lo ss of concentrating capacity by the kidney following uranium

exposure. Biochemical changes include diminish ed activity of important enzymes (such as

alkaline phosphatase), which can persist for seve ral months after exposure has ended. Therefore,

acquired tolerance to uranium may not prevent chronic damage, because the kidney that has

developed tolerance is not normal [Leggett 1989]. Ac ting on the basis of this recent information

for uranium, researchers have sugge sted that exposure limits be reduced to protect against these

chronic effects on the kidney.

Renal damage appears to be definite at concen trations of uranium pe r gram of kidney tissue

above 3 μ g/g for a number of different animal speci es, but mild kidney injury can occur at

uranium concentrations as low as 0.1 to 0.4 μ g/g in dogs, rabbits, guinea pigs, and rats after they

inhale uranium hexafluoride or uranium tetrachloride over several months [Maynard and Hodge

1949; Hodge 1953; Stokinger et al. 1953; Diamond 1989]. Zhao and Zhao proposed a limit of

uranium to the kidney of 0.26 μ g/g based on renal effects in a man who was exposed to high

concentrations of uranyl tetraf luoride dust for 5 minutes in a closed room [Zhao and Zhao 1990].

The man showed signs of kidney toxicity, incl uding increased protein content in the urine

(proteinuria) and nonprotein nitrogen. These signs persisted for 4.6 years, gradually returning to

normal values. The kidney content 1 day after the accident was estimated to be 2.6 μ g/g.

A study conducted in Finland and published in 2002 observed 325 people that had used their

drilled wells for drinking wa ter over a period of 13 years on average (range 1 – 34 years)

[Kurttio et. al 2002]. The median uranium con centration in the water was 28 ppb (range 0.001 –

57Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 1,920 ppb). The study showed an association between increased uranium exposure through

drinking water and tubular func tion, but not between uranium exposure and indicators of

glomerular injury. The primary target is the pr oximal convoluted tubule of the kidney which is

where most of the sodium, water, glucose, and other filtered substances are reabsorbed and

returned to the blood. The author s of the study indicated that tubular dysfunction may merely

represent a manifestation of subclinical toxici ty, and it is unclear if it carries a risk of

development into kidney failure or overt illness. This study concluded that “The public health

implications of these findings remain uncertai n, but suggest that the safe concentration of

uranium in drinking water may be close to th e guideline values proposed by the WHO and the

U.S.EPA.” However, this study found that altered tubular function was statistically significant at

water uranium concentrations exceeding 300 μ g/L [Kurttio et. al 2002], or 0.3 mg/L, which is an

order of magnitude higher than EPA’s gui deline (0.035 mg/l) and the highest average

concentration at the Lincoln Park site (0.048 mg/L). At 300 μ g/L and assuming ingestion of two

liters of water per day, the kidney burden afte r 25 years of chronic ingestion would be 39.6 μ g of

uranium with a uranium concentratio n per gram of kidney tissue of 0.13 μ g/g.

A review of studies of uranium effects on th e kidney [Morris and Meinhold 1995] suggests a

probability distribution of threshold values for kidney toxicity ranging from 0.1 to 1 μ g/g, with a

peak at about 0.7 μ g/g. The researchers proposed that the severity of effect s increases with

increasing dose to the kidney with probably no effects below 0.1 to 0.2 μ g/g, possible effects on

the kidney at 0.5 μ g/g, more probable effects at 1 μ g/g, and more severe effects at 3 μ g/g and

above [Morris and Meinhol d 1995; Killough et al. 1998b].

If an adult in Lincoln Park drank 2 liters (L) of uranium-contaminated water per day (at the

highest average exposure concentration of 0.048 mg /L, or 48 μg/L) for 25 years or longer, then

the maximum daily ingestion would be 96 μg of uranium, resulting in a uranium kidney burden

of 6.3 μg (96 μg × 0.066). The weight of both kidneys in adults is about 300 g [Madsden et al

2007]. Thus, the uranium concentration per gram of kidney tissue for an adult would be 0.02

μg/g. If a child drank 1 L of uranium-contam inated water per day (at the highest average

exposure concentration of 0.048 mg/L, or 48 μg/L) for 100 days to 25 years, then the maximum

daily ingestion would be 48 μg of uranium, re sulting in a uranium kidney burden of 1.4 μg (48

μg x 0.03). The weight of both kidneys in a ch ild is about 100 g; therefore, the uranium

concentration per gram of kidney tissue to be 0.01 μg/g. The calculated kidney uranium

concentration for adults and children is below th e level found to cause harm in published studies.

ATSDR’s health-based guidelines for ingested (and inhaled) uranium are lower than the lower

limit threshold for kidney toxicity propos ed by Morris and Meinhold (1995). ATSDR’s

guidelines are derived by use of levels of t oxicity observed in anim al studies, and those

guidelines incorporate safety factors to account for uncertainty in extrapolating from animals to

humans and to protect the most sens itive human individuals [ATSDR 1999].

Note that urinalysis has limitations as a test for kidney toxicity. First, the presence of substances

in urine may indicate that kidney damage has occurred, but it cannot be used to determine

whether the damage was caused by uranium. Sec ond, most uranium leaves the body within a few

days of exposure, so that urine tests can be used only to determine whether exposure has

occurred in the past week or two. Finally, the te sts may be used to detect mild effects on the

kidney, but such effects are gene rally transient in nature and may not result in permanent

58Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### damage. More severe effects involve greater damage to the kidney th at is likely to be clinically

manifest and longer lasting. The kidney has incr edible reserve capacity and can recover even

after showing pronounced clinical symptoms of damage; however , biochemical and functional

changes can persist in a kidney that appears to have recovered structurally [Leggett 1989, 1994;

CDC 1998].

The maximum average uranium concentration de tected in a private well was 0.048 mg/L, or 48

μg/L. The residence where this concentration wa s detected is not connected to the municipal

water supply and is noted to use a private we ll for personal consumption. Drinking water from

this private well containing uranium would result in an estimated dose of 0.001 mg/kg/day for an

adult and 0.003 mg/kg/day for a child. The adult dos e is lower than the in termediate oral MRL.

The estimated child dose slightly exceeds the MRL of 0.002 mg/kg/day for an intermediateduration oral exposure. The MRL level for intermed iate-duration oral expos ure is also protective

for chronic-duration oral exposure because the renal toxicity of uranium exposure is more

dependent on the dose than on the duration of the exposure. The MRL is based on a LOAEL of

0.05 mg U/kg/day for renal effects in rabbits. The estimated child dose is an order of magnitude

lower than the LOAEL; therefore, ad verse health effects are not likely.

Although older evaluations suggested carcinogenicity of uranium among smokers, the U.S. EPA

has withdrawn its classification for carcinogenicity for uranium; the International Agency for

Research on Cancer (IARC) and the Nationa l Toxicology Program (NTP) have no ratings

[NHANES 2005].

D. Soil Pathway: Surface Soil near Cotter Mill and Lincoln Park

As discussed above, surface soil samples were collected from areas around the Cotter Mill

property, from property access roads and in the Lincoln Park area. Surface soil sampling data

were available from eight desi gnated zoned areas around Cotter Mill and in Lincoln Park. People

who live or recreate in these areas could accidentally ingest some contaminated soil or get it on

their skin. ATSDR evaluated these potential exposure scenarios to determine if concentrations of

chemicals and radionuclides in soil are high enou gh to cause adverse health effects.

ATSDR assumed that the average adult would acci dentally ingest 100 milligrams of soil per day

and would also contact the contaminated soil with their skin (dermal). Small children were not

assumed to access the soil around Cotter Mill because these areas are primarily industrial or

vacant. The vacant area has been designated as a “buffer zone” between the Cotter Mill property

and the residential areas. Therefore, it is unlik ely that small children would access the area. A

residential exposure scenario was used to eval uate potential exposures in Lincoln Park. For

Lincoln Park, we assumed that a small child would inge st 200 mg of soil per day, and an adult

would ingest 100 mg/day, for 350 days per year.

Concentrations of arsenic, cadmium and lead ex ceeded their comparison values in soil taken

from the area surrounding Cotter Mill. The concentration of radium-226 was the only

radionuclide to exceed its comparison value in soil near Cotter Mill. Arsenic was the only

chemical to exceed its comparison value in so il in Lincoln Park. The highest zonal average

concentration of arsenic, cadmium, lead and radi um-226 was used to estimate exposure doses. If

59Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### the highest zonal average concentration of a chemi cal would not result in a dverse health effects,

it follows that lower concentrations of the chemical would not as well.

1. Soil Near Cotter Mill

a) Arsenic

Arsenic is a naturally occurring element that is widely distributed throughout the earth’s crust

and may be found in air, water, and soil [ATSDR 2000]. Arsenic in soil exists as inorganic and

organic arsenic. Generally, organic arsenic is less toxic than inor ganic arsenic, with some forms

of organic arsenic being virtually non-toxic. Inorganic arsenic occurs naturally in soil, and

children may be exposed to arsenic by eating soil or by direct skin contact with soil containing

arsenic [ATSDR 2007].

The estimated dose of arsenic for adolescents and adults at this site is 0.00002 mg/kg/day. This

dose is lower than the Minimal Risk Level (M RL) of 0.0003 mg/kg/day for arsenic; therefore,

non-cancer health effects are not likely from being exposed to arsenic in surface soil near Cotter

Mill (Zones A through H). The chronic oral MRL of 0.0003 mg/kg/day for inorganic arsenic was

derived by dividing the identified chronic No Ob servable Adverse Effect Levels (NOAEL) of

0.0008 mg/kg/day (obtained from human epidemiologic studies) by an uncertainty factor of three

to account for the lack of data on reproductive toxicity and to account for some uncertainty as to

whether the NOAEL accounts for all sensitive individuals [ATSDR 2007]. The Lowest Observed

Adverse Effect Level (LOAEL) associated with these epidemiologic studies was 0.014

mg/kg/day, where exposure to arse nic above this level resulted in hyperpigment ation of the skin,

keratosis (patches of hardened skin), and po ssible vascular complicat ions [ATSDR 2007].

The U.S. Environmental Protection Agency (EPA ), the International Agency for Research on

Cancer (IARC), and the National Toxicology Pr ogram (NTP) classify arsenic as a human

carcinogen. The EPA has developed an oral cancer slope factor to estimate the excess lifetime

risk for developing cancer. Using EPA’s cancer sl ope factor for arsenic, and based on a 30 year

exposure scenario, ATSDR calculated a lifetim e estimated cancer risk level of 1 x 10 -5 

### for

exposure to arsenic in soil near Cotter Mill. Qu alitatively, we interpre t this as a very low

increased lifetime risk of developing cancer.

b) Cadmium

The estimated dose for adolescents and adul ts for cadmium is 0.00002 mg/kg/day, which is

lower than the MRL of 0.0001 mg/ kg/day for cadmium; therefore, non-cancer adverse health

effects are not likely. The U.S. Department of Health and Human Services (DHHS), IARC, and

EPA have determined that cadmium is carci nogenic to humans. Although cadmium can be

carcinogenic when inhaled, human or animal studi es have not provided sufficient evidence to

show that cadmium is a carcinogen by oral rout es of exposure (ATSDR 1999b). Therefore, a

cancer evaluation for cadmium was not done as part of this assessment.

c) Lead

The highest average concentration of lead detect ed in any of the zones (Zone H) is 445 ppm,

which is only slightly higher th an the soil screening value of 400 ppm for lead. A value of 400

60Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### ppm is commonly used to evaluate lead in soil in residential properties. The property near the

Cotter Mill site is currently restricted, vacant or used for industrial pur poses; therefore contact

with these soils should be minimal. Adverse hea lth effects are not expected to occur from these

limited exposures to soils near the site. Exposures to lead, however, should be re-evaluated

should the area ever be considered for residential or other non-industrial use.

Maximum lead concentrations in zones F, G and H are 800 ppm, 450 ppm, and 1,400 ppm,

respectively. To protect children from exposure to lead, it is im portant to know the average lead

level in a yard or other frequent play area. The 1998 Supplemental Human Health Risk

Assessment provides the only characterization of surface soils adjacent to the Cotter Mill

property (See Figure 17, Zones A through H). The soil sample results in this report were

generated by collecting four samples from the center of a grid and compositing the samples to

form a single representative sample. The size of each sampled grids, however, appears to be

larger than 100 x 100 feet, which is the size th at triggers additional sampling for lead (EPA

1995). Although the sampling in the 1998 Supplemental Human Health Risk Assessment

measured contamination in soils at several prope rties near Cotter Mill, it does not allow ATSDR

to evaluate contamination in individual exposur e units (yards, playground s, etc), as would be

required to accurately assess exposures in a residential setting, commercial or recreational

setting. The sample design is sufficient for ma king general public he alth decisions about

exposure to lead in soil based on current use patte rns. However, any future public health decision

regarding the soil near the Cotter Mill property must be made with the limitations of the current

sampling design in mind.

The Centers for Disease Control and Prevention (CDC) has established a level of concern for

case management of 10 micrograms lead per decilit er of blood (μg/dL). This means that when

blood lead levels in children exceed 10 μg/dL, CDC recommends that step s be taken to lower

their blood lead levels. However, some agencies a nd public health officials have mistakenly used

this level in blood as a safe leve l of exposure or as a no effect le vel. Recent scientific research

has shown that blood lead levels below 10 μg /dL cause serious harmful effects in young

children, including neurological, behavioral, immunological, and development effects.

Specifically, lead causes or is associated with decreases in intelligent quotient (IQ), attention

deficit hyperactivity disorder ( ADHD), deficits in reaction time, visual-motor integration, fine

motor skills, withdrawn behavior, lack of concentration, sociabil ity, deceased height, and delays

in puberty, such as breast a nd pubic hair development, and delays in menarche [CDC].

d) Radium-226

The average concentrations of radium-226 detect ed in Zones A and B are higher than allowed by

the Uranium Mill Tailing Act (UMTRA). That sta ndard does not apply in this case, since the

Cotter Mill is still considered active.

The highest average soil concentr ation of 9.2 pCi/g in surface soil would result in a dose from

radium’s decay gammas of 58 mrem per year above background, assuming that residents spend

12 hours per day 365 days per year sitting or lying on the highest measured radium concentration

of 9.2 pCi/g on the haul road. Since Zones A a nd B are buffer areas (actually haul roads), the

time spent in these areas would be much lower (l ess than 2 hours per day) and the resulting dose

would be roughly 10 mrem per year above b ackground, to a maximally exposed individual.

61Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 2. Soil in Lincoln Park

a) Arsenic

The estimated arsenic dose for an adult in Linc oln Park is 0.00003 mg/kg/day, which is an order

of magnitude lower than the MRL of 0.0003 mg/kg/day for arseni c. The estimated arsenic dose

for a child in Lincoln Park is 0.0003 mg/kg/day, which is equal to the MRL of 0.0003 mg/kg/day

for arsenic. Children are estimated to have higher arsenic doses than adults because they tend to

engage in activities that increase their soil inge stion exposure, and because they weigh less than

adults. Neither children nor adults should expe rience adverse health effects from exposure to

arsenic in soil in Lincoln Park.

Arsenic is a naturally occurring el ement in soil. Arsenic has also historically been used in a

variety of industrial applications, including bronze plating, elect ronics manufacturing, preserving

animal hides, purifying industrial gases, and mi ning, milling and smelting activities. Studies of

background levels of arsenic in so ils have revealed that backgr ound concentrations range from 1

ppm to 40 ppm, with average values ar ound 5 ppm [ATSDR 2007]. The average arsenic

concentration detected in Lincoln Park wa s 31 ppm, a concentration within the observed

background range but higher than the aver age background concentr ation. The maximum

concentration of arsenic detected in Lincoln Park was 50 ppm.

Although the maximum arsenic concentration is higher than the observed background

concentration, this fact alone doe s not definitely point to an an thropogenic source for the arsenic

found in soil in Lincoln Park. Uncertainty exists regarding whether the ar senic levels detected

are a natural occurrence or from pa st milling operations in the area.

Several factors contribute to whether people ha ve contact with contaminated soil, including:

 grass cover, which is likely to reduce contac t with contaminated soil when grass cover is

thick but increase contact with so il when grass cover is sparse or bare ground is present,

 weather conditions, which is likely to reduce co ntact with outside soil during cold months

because people tend to stay indoors more often,

 the amount of time someone spends out side playing or gardening, and

 people's personal habits when outside, for inst ance, children whose play activities involve

playing in the dirt are likely to have greater exposure than other children

Using EPA’s cancer slope factor for arsenic, an d based on a 30 year exposure scenario, ATSDR

calculated a lifetime estimated cancer risk level of 5 x 10 -5 

### for exposure to arsenic in Lincoln

Park. Qualitatively, we interpret th is as no apparent increased life time risk of developing cancer.

E. Surface Water: Sand Creek, DeWeese Dye Ditch, and the Arkansas River

People who swim or wade in the surface waters of Sand Creek, the DeWeese Dye Ditch, or the

Arkansas River will get surface water on their skin and they might also accidentally ingest some

of the surface water. To estimat e exposures to adults and chil dren who may have come into

62Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### contact with contaminated surface water, ATSDR assumed that adults and children will swallow

50 mL of water per hour while swimming or wading, for 104 days per year for 30 and 6 years,

respectively. Molybdenum exceeded its comparison value in Sand Creek and the Arkansas River.

Manganese exceeded its comparison value in Sand Creek and the DeWeese Dye Ditch. ATSDR

conservatively selected the maximum concentra tion for each chemical to estimate exposures.

1. Manganese

The estimated exposure dose for manganese is 0.0007 mg/kg/day for adults and 0.0006

mg/kg/day for children. Both adult and child dos es are considerably lower than the reference

dose of 0.05 mg/kg/day for manganese. Therefore, no adverse health eff ects are expected to

occur as a result of exposure to manganese in surface waters.

2. Molybdenum

The estimated exposure dose for molybdenum is 0.00002 mg/kg/day for adults and 0.00006

mg/kg/day for children. Both adult and child dos es are below the chronic oral reference dose

(RfD) of 0.005 mg/kg/day for mol ybdenum. Therefore, no adverse hea lth effects are expected to

occur as a result of exposure to molybdenum in surface waters.

F. Homegrown Fruits and Vegetables

Ingestion of contaminated foods is a potential exposure pathway for this site. Residents may

have been exposed to contaminants when they ate homegrown fruits and vegetables after using

contaminated groundwater (either surface water or pr ivate well water) to ir rigate their crops, or

after growing their crops in contaminated soil. The soil may become contaminated from

contaminated water or from tailings, dusts and ot her wastes deposited in the soil in the past.

Eating fruits, vegetables, herbs, or other produc e grown in gardens with contaminated soil can

cause exposure. This type of exposure occurs be cause some plants slowly absorb small amounts

of the chemicals found in soil into their plant tissu e or because contaminated soil can adhere to

the exterior surface of produce, particularly low-growing leafy produce or produce where the

underground portion is eaten. Some of these absorbed chemicals are essential nutrients and are

actually good for humans to eat, but other chemicals can present he alth hazards if they are found

at high enough levels and are c onsumed on a regular basis.

Generally, there is not a strong relationship between levels of heavy metals in soils and plants

[Vousta 1996]. The uptake of heavy metal concentr ation depends on speciation of metal, soil

characteristics, the type of plant species and other characteristics [Laizu 2007]. Table 8 below

developed by Sauerbeck (1988) provides a qual itative guide for assessing heavy metal uptake

into a number of plants.

63Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 8. Plant Uptake of Heavy Metals

High Moderate Low Very Low

Lettuce Onion Corn Beans

Spinach Mustard Cauliflower Peas

Carrot Potato Asparagus Melons

Endive Radish Celery Tomatoes

Crest Berries Fruit

Beet

Beet leaves

Source: USEPA (1991), Human Health Evaluatio n Manual, Supplemental Guidance: “Standard

Default Exposure Factors 

### .”

To address the concern regarding contaminated crops, residents cont ributed locally grown

produce for sampling analysis. ATSDR used the sampling results to estimate an exposure dose

for each contaminant using typical consumption rates for the average and above-average (95 th



### percentile) consumer in the Western United States . Child and infant consumption rates were also

used to assess exposures to these vulnera ble populations. Table 9 below provides the

consumption rates used by ATSDR for homegrown fruits and vegetables.

Table 9. Homegrown Fruit and Vegetable Cons umption Rates for the Western United States

Food Consumer Type† Intake Rate

(g/kg/day) Standard Error

Homegrown fruits Average consumer 2.62

0.3 Above-average

consumer 10.9

Child 4.1

NA Infant (1 to 2 years) 8.7

Homegrown

vegetables Average consumer 1.81

0.1 Above-average

consumer 6.21

Child 2.5

NA Infant (1 to 2 years) 5.2

Sources: EPA Exposure Factors Handbook, Volume II, 1997; Child-Specific Exposure Factors Handbook, 2008

g/kg/day: grams per kilogram per day

NA = not applicable



### † An average consumer is represented here as a person who eats fruits and vegetables in the typical range

(mean intake). An above average consumer is a person w ho eats more fruits and vegetables than is typical,

represented here by the 95 th

percentile intake.



### All of the estimated fruit and vegetable doses were below health guide line values except for

those for arsenic (See Table C4 in Appendix C) . The estimated doses for fruits for the aboveaverage consumer (95 th 

### percentile intake rate) and for infa nts exceed the chronic health guideline

64Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### for arsenic. The above-average consumer and infant doses for fruit are 0.0006 mg/kg/day and

0.0004 mg/kg/day, respectively. Also, the estimated doses for vegetables for the above-average

consumer (95 th 

### percentile intake rate) and for infants exceed the chronic health guideline for

arsenic. The vegetable doses are 0.0005 mg/kg/ day for an above-average consumer and 0.0004

mg/kg/day for an infant. These doses exceed the chronic oral MRL of 0.0003 mg/kg/day for

arsenic.

Next, ATSDR assumed that a person will eat both fruits and vegetables daily. To do this, we

added the calculated doses for fruits and vegetabl es to derive a single dose. The estimated fruit

and vegetable doses for the above-average consumer, child and infant exceed the health

guideline of 0.0003 mg/kg/day for arsenic. The above-average consumer dose is 0.001

mg/kg/day; the child dose is 0.0004 mg/kg/day; and the infant dose is 0.0008 mg/day/day.

The chronic oral MRL of 0.0003 mg/kg/day for i norganic arsenic was de rived by dividing the

chronic No Observable Adverse Effect Leve l (NOAEL) of 0.0008 mg/ kg/day (obtained from

human epidemiologic studies) by an uncertainty f actor of 3 to account for the lack of data on

reproductive toxicity and to account for some unc ertainty as to whether the NOAEL accounts for

all sensitive individuals [ATSDR 2007]. The Lowest Observed Adverse Effect Level (LOAEL)

associated with these epidemiologic studies was 0.014 mg/kg/day, wher e exposure to arsenic

above this level resulted in hyperp igmentation of the skin, keratosis (patches of hardened skin),

and possible vascular complicati ons [ATSDR 2007]. The child a nd infant doses are below or

equal to the NOAEL, and the above-average consum er dose is 14 times lower than the dose that

caused adverse health effects in epidemiologic st udies. Therefore, adverse health effects are not

expected in infants, children or the above-average consumer.

Using EPA’s cancer slope factor for arsenic and the above consumer exposure dose, and based

on a 30 year exposure scenario, ATSDR calculated a lifetime estimated cancer risk level of 6 x

10 -4 

### for exposure to arsenic in fruits and vegetables . Qualitatively, we interpret this as a low to

moderate increased ri sk of developing cancer over a lifetime.

ATSDR conservatively assumed that every consum er ate homegrown fruits and vegetables every

day for 30 years. In reality, it is likely that mo st people only eat homegrown fruits and vegetables

during a defined season, usually a 3 to 4 mont h period during the summer/fall growing season.

Therefore, the true risk to c onsumers is likely overestimated.

ATSDR also noted that the highest arsenic level detected in lawn s and gardens in Lincoln Park

was 50 ppm. This level is near what is typically observed as background arsenic levels (1 ppm to

40 ppm) in soil. This suggests that the contamin ated well water used to irrigate crops is not

contributing significantly to arsenic soil levels, or other soil additives may have been added that

dilute soil contamination [ODEQ 2003]. The highest arsenic level detected in soil at the site was

86 ppm. There were no sampling data for arseni c in drinking or irriga tion water. ATSDR is

unsure if the arsenic found in soil at this site is a natural occu rrence or from an anthropogenic

(man-made) source.

Plants vary in the amount of arsenic they abso rb from the soil and where they store arsenic.

Some plants move arsenic from th e roots to the leaves, while othe rs absorb and store it in the

roots only [Peryea 1999]. The best method of reduc ing exposure to external arsenic from home

65Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### grown vegetables is to soak and wash residual soil from produce before bringing it into the home

and washing the produce again thoroughly indoors before eating [ATSDR 2007]. It is always a

good health practice to wash all fr uits and vegetables thoroughly before eating, whether they are

bought or homegrown.

Molybdenum was the only other cont aminant to approach a health guideline when calculating a

single dose for fruits and vegetables. The a bove-average consumer and infant doses are

0.005mg/kg/day, which is equal to the chroni c health guideline of 0.005mg/kg/day for

molybdenum.

G. Air Pathway

ATSDR looked at all the air data collected from 1979 to present. Concentrations of radionuclides

in air from direct release or re -suspension of radioactive contamin ants in soil were less than a

tenth of ATSDR’s health based comparison value (100 millirem per year) at all off-site sampling

locations (CC-1/2, LP-2, AS-210, AS-212, OV-3). AT SDR evaluated doses to all age groups and

found that adults would have received the highe st doses, because of th eir higher breathing rate.

Infants only received one quart er the dose of an adult.

Table 10 below breaks down the dose estimate s by age group and by the highest annual

concentration measured for each radionuclide and by the highest location. The two highest doses

were both in 1982, during the excava tion of the unlined settling ponds and were measured at the

on-site sampling location AS-204, that was direc tly adjacent to the dewatered ponds. Neither of

those doses would have been to the public. The combined dose to a worker near AS-204 would

have been less than a third of the sum in the table since the wo rker was there less than 8 hours

per day for 5 days a week, or 70 mrem of inhala tion dose for the year 1982, while the numbers in

Table 10 reflect 24/7 exposure th rough the year. Doses listed in Table 10 did not result in any

elevated exposures to the public.

Table 10. Annual Effective Doses by Highest Concentration, Location and Age Group

Radionuclide Highest

Year Highest

Location Concentration

(μCi/ml) Dose to

Infant

(mrem/yr) Annual

Dose to

Adult Notes

Natural Uranium

(μCi/ml) 1979 AS-204 2.48E-14 2.72 5.97

Thorium-230

(μCi/ml) 1982 AS-204 8.95E-14 71.57 272.68

Thorium-232

(μCi/ml) 2001 CC#2 8.33E-17 0.07 0.27

Radium-226

(μCi/ml) 1985 AS-202 9.63E-15 1.25 2.75

Lead-210

(μCi/ml) 1982 AS-204 9.95E-14 7.01 16.77 Dose from

Radon Progeny

Radon-220/222

(pCi/l) 2004 AS-202 1.50E+00 NA NA No dose from

Radon



### Most of the calculate d inhalation dose was from the is otope Thorium-230 (Th-230). Table 11

below lists just the dose from Th-230 for th e highest annual average concentration at each

66Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### sampling station. Again it can be se en that the on-site concentrati ons are consistently orders of

magnitude higher than at off-site locations in Cañon City, Lincoln Park and west of the site

boundary.

Outdoor concentrations of radon c ontributed zero dose to the public, because it is a noble gas and

does not stay in the lungs long enough to radioactively decay. On the other hand, the dose from

radon decay products (e.g., lead-210) attached to resp irable dust held constant year over year and

accounted for an annual inhalation dose of four to seven millirem annually. Radon decay product

concentration off-site did not appear to be rela ted to releases from the site. Radon and its decay

products appear to be from natural background a nd do not represent any h ealth threat at the

reported concentrations.

Table 11. Annual Doses from Thorium-230 by Location and Year

Year Highest

Location Concentration

(μCi/ml) Annual Dose to Infant

(mrem/yr) Annual Dose to

Adult(mrem/yr)

1982 AS-204 8.95E-14 71.57 272.68

1982 AS-202 2.12E-14 16.95 64.59

1983 AS-203 9.79E-15 7.83 29.83

1982 AS-206 1.26E-14 10.08 38.39

2000 AS-209 4.16E-15 3.33 12.67

2005 AS-210 4.85E-16 0.39 1.48

2000 AS-212 6.69E-16 0.53 2.04

1982 LP-1/2 7.49E-16 0.60 2.28

1982 CC-1/2 9.18E-16 0.73 2.80

1982 OV-3 3.15E-15 2.52 9.60

67Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## VI. COMMUNITY HEALTH CONCERNS

Responding to community health concerns is an essential part of ATSDR’s overall mission and

commitment to public health. The community asso ciated with a site is both an important

resource for and a key audience in the public health assessment process. Community members

can often provide information that will contribu te to the quality of the health assessment.

Therefore, during site visits and telephone conversations wi th community members, ATSDR

obtained information from the community regarding their specific health concerns related to the

site.

In some cases, ATSDR was unable to address a co mmunity health concern because 1) adequate

scientific information on the particular health effect is not available or is limited or 2) the

available scientific data are insu fficient to assess whether the speci fic health effect is related to

exposure to a particular chemical. Where feas ible, ATSDR addressed the health concerns

identified by the community. Below is a summ ary of the community concerns and ATSDR’s

response to those concerns.

1. How did the 1965 flood event affect my health?

In June 1965, prior to the c onstruction of the SCS Dam in 1971, a flood caused the unlined

tailings ponds at the Cotter Mill to overflow in to Lincoln Park. Accordin g to the residents, the

waters flowed north thr ough the gap in the ridge,

down Pine Street, and ultimately down 12 th 

### Street

(Sharyn Cunningham, CCAT, personal

communication, February 2008). There is concern

that this flood event contaminated groundwater

wells and that dust from soil or tailings may have

been resuspended by wind and distributed in

Lincoln Park. Community members are very

concerned that current illnesses may be a result of

this tailings pond flood event.

ATSDR tried to locate data to evaluate the

potential health effects resulting from this flood

event. No data from 1965 or 1966 exist in the

CDPHE database. The 1986 Remedial There is documentation that ponds at the

Cotter Mill historically overflowed, which led

to the construction of the SCS Dam. Aerial

photography from October 1970 indicates

that one of the evaporation ponds

overflowed into an alluvial channel tributary

to Sand Creek (Wilder et al. 1983). A

chronology compiled by CDPHE states that

in October 1970 and January 1971, an

evaporation pond overflowed with high

levels of total dissolved solids, sodium,

molybdenum, sulfate, and high radiation

(CDPHE 1975).However, since the

construction of the SCS Dam, there are no

recorded surface water discharges past the

dam (GeoTrans 1986).



### Investigation (GeoTrans 1986) states that off-site groundw ater contamination in the Lincoln Park

areas was first identified in 1968; therefore, any data prior to 1968 are unlikely to exist. The only

data ATSDR found related to this flood event were from a sediment sample collected in January

2003 (CDPHE 2003). To address community concerns , CDPHE collected a sample of suspected

flood sediment from Pine Street near Elm Avenue. This area was identified by a property owner

who was present during the flood. The sample was collected from two locations. About 250

grams of soil were collected from each location to a depth of approximately 18 inches. No

obvious soil horizons were identif ied, and no significant differences in gamma radiation were

noted between shallow and deep soils. The re sults are presented in Table 12 below. All

concentrations from this one sample are below comparison values.

68Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### The results of the sediment sample from the fl ood did not exceed any comparison values. If this

sample was representative of the material moved by the floodwaters, it would not cause any

adverse health effects.

Table 12. Concentrations found in a suspected flood sediment sample, January 2003

Chemical Concentration (ppm) Comparison Value (ppm)

Lead 87 400

Molybdenum Not detected 300

Uranium 1.6 100

Radionuclide Concentration (pCi/g) Comparison Value (pCi/g)

Cesium-137 0.12 Not available

Lead-210 2.2 Not available

Plutonium-239, 240 Not detected Not available

Potassium-40 22.5 Not available

Radium-226 2.2 15

Radium-228 1.3 15

Source: CDPHE 2003



### 2. Were an adequate number of soil samples collected during the 1998 Supplemental

Human Health Risk Assessment ?

The community expressed concern that not enough samples were collected during the 1998

Supplemental Human Health Risk Assessment . Weston, a contractor for Cotter, collect ed surface

soil samples (0-2 inches) from eight zones around the mill property (see Figure ). Each zone was

divided into 8 to 12 grids. Four samples were collected near the center of each grid and were

composited (i.e., combined and homogenized) to form a single representative sample (Weston

1998). The dates the samples were collected were not specified in the report; however, it is

assumed to be in the 1994–1996 timeframe. In 1995, EPA released guidance for obtaining

representative soil samples at Superfund site s (EPA 1995). The systematic grid sampling

approach used by Weston conforms with EP A’s guidance for delineating the extent of

contamination. The number of samples taken from each grid for compositing, however, is not

entirely consistent with EPA’s guidance. For gr ids larger than 100 x 100 feet, which it appears

that the grids established by Weston are, EPA re commends collecting nine aliquots from each

grid. Compositing four aliquots from each grid is recommended for grids smaller than 100 x 100

feet (EPA 1995). Because the tim eframe of the sampling is unclear, it is not known whether

EPA’s 1995 guidance was available during Weston’s sampling effort.

3. Are there high levels of thor ium near the Black Bridge?

The community expressed concern th at high thorium levels were de tected in surface water near

the Black Bridge. This bridge is located wher e a railroad spur crosses the Arkansas River

between the 4 th 

### Street and 9 th 

### Street bridges. The closest sampli ng location in the Arkansas River

is upstream at 1 st 

### Street (907). Thorium-230 was sampled at this location as part of the surface

water monitoring program between 1995 and 2007. Th ese data are summarized below in Table

13. The highest thorium-230 concentration detected was 2.5 picocuries per liter (pCi/L)

69Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### (suspended sample) in August 2007. This concentra tion is below levels known to cause adverse

health effects. It should also be noted that the Black Bridge is located upstream of the confluence

with Sand Creek.

Table 13. Thorium-230 data upstream of the Black Bridge

Chemical Frequency of

Detection Minimum

(pCi/L) Average

(pCi/L) Maximum

(pCi/L)

Thorium-230 (D) 121/127 -0.1 0.1 1

Thorium-230 (S) 115/120 0 0.2 2.5

Thorium-230 (T) 7/7 0.1 0.3 0.7

Source: CDPHE 2007b

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Negative and zero result values were included in the summary statistics.

Thorium-230 “D” and “S” samples were collected between 1995 and 2007. Thorium-230 “T” samples were only

collected in 1995.

D – dissolved S – suspended

pCi/L – picocuries per liter T – total



### 4. I grew up near the Cotter plant. Does th is increase my risk of getting cancer?

Soil sampling data from the nearest residence to th e Cotter plant did not indicate the presence of

chemicals at levels above established guideline s. Soil sampling data from the Lincoln Park

community did not reveal the presence of contaminan ts at levels associated with adverse health

effects, including cancer. Air data do not indicate the presence of chemicals at levels associated

with adverse health effects, including cancer. If you drank water from a contaminated private

well, you might be at increased risk for gout-like conditions, such as pain, swelling,

inflammation and deformities of the joints. Ho wever, once exposure is stopped, the risk of

adverse health effects goes down.

5. I used water from my private well or su rface water to irrigate my crops and garden

vegetables. Am I going to get sick?

According to our evaluation, people who ate fruits or vegetables irrigated with c ontaminated well

water are not at increased risk for non-cancer hea lth effects. However, people who eat more than

the average amount of fruits and vegetables (95 th 

### percentile consumers) might be at increased

risk for developing cancer ove r a lifetime. This conclusi on is based on a person eating

approximately 4 times more fruits and vegetables than the average person every day for 30 years.

People who grew fruits and vegetables at their ho me and used their well water to irrigate their

crops submitted crop samples for analysis. The analysis revealed that vegetables irrigated with

well water did not cause a signi ficant increase in contaminant levels (Weston 1998). As a

precaution, however, we recommend washing all home grown fruits and vegetables before eating

them.

70Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### 6. I have lived in Lincoln Park since the 1960s. I know of many neighbors and family

members who are sick. Is uranium fr om the mill making us sick?

Uranium primarily acts as a heavy metal toxin. Renal toxicity is the hallmark effect of uranium

exposure, specifically to the pr oximal tubules of the kidney. We looked at CDC’s Compressed

Mortality Database “WONDER” looking specifically at specific modes of kidney failure that

could be associated with uranium toxicity. Frem ont County in Colorado had an age adjusted rate

for renal failure as the cause of death of 7.1 per 100,000, for the years 1999-2006. The state

average during that same period was 12.1 per 100,000 13 

### . From the available health outcome data,

it does not appear that re sidents in the area have elevated rate s of kidney disease, which could be

associated with uranium exposure.

7. My husband worked at the plant. Was I possibly exposed when he brought his dirty

work clothes home?

Workers in industrial settings have the potenti al to expose their household members to workrelated chemicals if residues attach to the worker’s clothing, skin, s hoes, or in their vehicles and

is inadvertently brought into the home. Whether and to what magnitude these take-home

exposures actually occur depends on a number of factors, including the natu re of the job held by

the worker, the occupational practices of the industrial facility (e.g., providing workers with

disposable gowns and gloves), and the precautions /practices of the worker and other family

members. ATSDR did not evaluate potential exposures to workers’ families because the data

needed to quantitatively or qua litatively make a determination on potential health effects were

not available.

8. I used contaminated water from my privat e well water for many years as a potable

source of water for my family. Are we no w at risk for adverse health effects?

The levels of molybdenum were high enough in some wells to cause adverse health effects in

individuals who were exposed for many years. Once exposure is stopped, the risk of adverse

health effects goes down. Resident s, particularly individuals w ho do not take in enough dietary

copper or cannot process copper correctly, might be at increased risk for gout-like conditions.

The levels of other contaminants are too low to cause adverse health effects.

9. CCAT conducted a health survey and subm itted it to ATSDR. Why didn’t ATSDR

use the results of this survey to determine if people are experiencing adverse health

effects in the community?

The community organization CCAT conducted a health survey in 2004–2005. The survey

included responses from 239 indivi duals in the Lincoln Park area. Volunteers went door-to-door

in Lincoln Park and the surrounding areas to admi nister the health surv eys. Each person filled

out a survey and submitted it to a volunteer. A ta bulation of self-reported illnesses reported by

respondents included occurrences of cancer; lung, hea lth, skin, central ne rvous system, kidney,

and thyroid problems; reproducti ve issues, including chromosomal and congenital defects;

13 Centers for Disease Control and Prevention, National Ce nter for Health Statistics. Compressed Mortality File

1999-2006. CDC WONDER On-line Database, compiled fr om Compressed Mortality File 1999-2006 Series 20

No. 2L, 2009. Accessed at http://wonder.cdc.gov/cmf-icd10.html on Sep 30, 2009 10:42:05 AM

71Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### autoimmune disease, psychological disorders, and gout. Although ATSDR could not use the

survey to make conclusions about disease associa tions, we did use the survey results to focus our

attention and pursue a more in-depth scientific an alysis of the health co nditions identified by the

community.

While the CCAT health survey was a good effort by the community to examine the frequency of

their various health concerns, there are many issues that make it of limited use in determining the

prevalence of adverse health effects present in the entire community and their potential

associations with exposure to environmental contam inants. Some of these issues include the use

of a relatively small convenience sample, the lack of medical verification of self-reported health

outcomes, and the need for indivi dual-level exposure data. Conve nient samples are typically not

representative of the entire popu lation, so results cannot be extr apolated to the community.

People who participate in nonrandomized surveys su ch as this may provide biased information

because of perceived relationships between envi ronmental contamination or other risk factors

and their health. Many of the se lf-reported health outcomes measur ed in the survey are present

in most populations and are related to several different potential causes beyond environmental

exposures, such as lifestyle or genetics. Therefor e, without any assessment of exposure, it is not

possible to link the occurrence of di sease to environmental concerns.

10. CDPHE previously ordered Cotter to have all environmental samples analyzed by

an external laboratory until Cotter could demonstrate that its laboratory had

addressed various deficiencies. Why was this done and how did it affect the data

used by ATSDR?

Cotter’s license requires the company to collect and report a wide ra nge of environmental

measurements. Cotter’s own analyt ical laboratory conducted most of the measurements between

the late 1970s and the present. The main excepti on is that an external analytical laboratory

measured contamination levels in most of the samples collected in 2005 and 2006.

For many years, Cotter has participated in so -called “round robin” inter-laboratory performance

evaluations. As part of these ev aluations, selected environmental samples are split every calendar

quarter and simultaneously sent to Cotter’s la boratory and to three external analytical

laboratories for analysis. The measurement result s are then compared to assess the performance

of Cotter’s laboratory. CDPHE’s we bsite presents data from thes e inter-laboratory comparisons

from 2007 to the present. Earlier comparisons are not readily available, mostly because Cotter’s

laboratory was not analyzing samples throughout much of 2005 and 2006 and data from earlier

years have since been archived from CDPHE’s website.

In September 2008, Cotter submitted a letter to CDPHE documenting five quarters of interlaboratory comparisons for groundw ater samples [Cotter 2008]. These comparisons presented

“round robin” data for more than two dozen s ubstances or indicators, including uranium,

molybdenum, selenium, nitrate, and selected ra dionuclides. In some cases, Cotter’s laboratory

tended to measure higher concentrations than the other participating labor atories; but in other

cases, the opposite was observed. With one exception, the differences between the measurements

made by the various laboratories fell within the range typically observed or expected.

72Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### The exception is for molybdenum, for which Cotte r’s laboratory did not meet pre-established

comparability limits for the “round robin” sampling. Specifically, in two out of the five quarters

of samples that were collected, Cotter’s la boratory did not meet the acceptable limits. 14 

### In

contrast, the three external la boratories’ molybdenum measurem ents met the pre-established

comparability limits for all five quarters considered in this report. The table below presents the

specific concentration measurements for the two quarters of interest, and these measurements

show that (in these two instan ces) the molybdenum levels measur ed by Cotter were less than 50

percent of the average concentrations calcula ted from the three external laboratories’

measurements.

After CDPHE requested that Cotter investigate the issue further, Cotter prepared a written

response to the issue [Cotter 2009]. The response suggests that the poor performance on these

samples resulted from the analytical method us ed. Cotter uses atomic adsorption to measure

molybdenum levels in groundwater samples, and the external laboratori es used a different

method (inductively coupled plasma with mass spectrometry). When molybdenum

concentrations are below roughly 0.5 mg/L, Cotte r measures molybdenum by atomic adsorption

graphite furnace analysis; but at higher concentrati ons, analysis is by atomic adsorption flame

analysis. The two quarters with the poor comparisons both had concentration levels below 0.5

mg/L, leading Cotter to infer th at the underreporting was associat ed with the graphite furnace

analyses. In January 2009, Cotter proposed severa l measures that were believed to cause the

graphite furnace analyses to perform better, and CDPHE approved of the proposed remedy.

Overall, the “round robin” studies have demonstrated that Cotter’s analytic al laboratory met prespecified performance criteria for almost ever y one of the substances considered. Only for

molybdenum was a performance issue noted, and it appears that Cotter’s laboratory previously

used a method that would understate molybdenum concentrations, but typically only when those

concentrations were less than approximately 0.5 mg/L. This issue was observed for samples

collected between January 2007 and March 2008, but it likely also affected earlier samples that

Cotter’s laboratory analyzed; and this negative bi as should be considered in any uses of these

data. Measurements collected since this timefra me likely do not exhibit the same negative bias,

given the changes that Cotter propos ed to its analytical methods.

Inter-Laboratory Comparison Results for Molybd enum: First Quarter 2007 & First Quarter 2008

Parameter Analytical Laboratory

Cotter Laboratory #1 Laboratory #2 Laboratory #3

Inter-Laboratory Comparison for First Quarter 2007

Measurement 1 (mg/L) 0.012 0.0263 0.027 0.024

Measurement 2 (mg/L) 0.012 0.025 0.027 0.0232

Average (mg/L) 0.012 0.0257 0.027 0.0236

Avg across three comparison laboratories (mg/L) 0.025

Inter-Laboratory Comparison for First Quarter 2008

Measurement 1 (mg/L) 0.01 0.0281 0.029 0.0267

Measurement 2 (mg/L) 0.011 0.0274 0.029 0.0274

Average (mg/L) 0.011 0.0278 0.029 0.0271

Avg across three comparison laboratories (mg/L) 0.028

Note: Every laboratory was supposed to analyze each sample twic e, thus providing data allowi ng for intra-laboratory and inter-l aboratory comparisons.

14 CDPHE actually voiced concern about th ree quarters of Cotter’s molybdenum da ta, even though only two of these

three quarters did not meet the pr e-established comparability limits.

73Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## VII. CONCLUSIONS

ATSDR reached four important conclusions in this public health assessment:

1. ATSDR concludes that drinking water for ma ny years from contaminated private wells

could harm people’s health. This is a public health hazard.

Private well sampling data collected from 1984 to 2007 revealed the presence of

molybdenum at levels that could harm peopl e’s health. A water use survey conducted in

Lincoln Park in 1989 revealed that at leas t seven people used groundwater (from their

private wells) for personal consumption. Th ese and other residents whose private wells

were affected by the highest molybdenum cont amination may be at increased risk for

health effects such as gout-l ike conditions, partic ularly individuals who do not take in

enough dietary copper or cannot process copper correctly.

The lack of consistent monitoring over the years and the unknown us age of wells before

the installation of the public water supply make these past exposures difficult to

accurately assess.

Most town residents are now connected to th e public water supply and have eliminated

their exposure to the contaminated well water. However, some reside nts are reported to

have refused public water supply connectio ns, and many may still have operational

private wells. Additionally, no formal institu tional controls exist to control groundwater

use in Lincoln Park. Therefore, current and future uses of private wells for domestic

purposes are still possible.

2. ATSDR concludes that accident ally eating or touching soil an d sediment near the Cotter

Mill property or in Lincoln Park will not harm people’s health. However, ATSDR cannot

make conclusions about soils near Cotter Mill if the properties closest to the facility are

developed for residential or other no n-industrial uses in the future.

3. ATSDR concludes that eating lo cally-grown fruits and vegeta bles irrigated with private

well water will not harm most people’s heal th. However, a person eating above-average

amounts of fruits and vegetables (4 times the average consumer) might have a low

increased risk for developing cancer over a lifetime. As a precaution, residents should

limit their use of contaminated well water to irrigate their crops. In all cases, the crops

should be thoroughly clea ned prior to eating.

4. ATSDR concludes that ambient air emissions of particle bound ra dionuclides have not

resulted in completed exposures to the public at levels that could cause adverse health

outcomes. With the exception of thorium-230 levels observed in 1981 and 1982,

associated with excavation of contaminated tailings, every radionuclide monitored has

been more than a factor of ten below annua l dose based health limits to the public. The

excavation releases appear to have only exposed on-site worker s, but still below

occupational limits at that time.

74Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## VIII. RECOMMENDATIONS

Based upon ATSDR’s review of the environmen tal data and the concerns expressed by

community members, the following recommendati ons are appropriate an d protective of the

health of residents in and around the Lincoln Park area.

 Residents should be informed about the health risks associated with contaminated private

wells and advised to connect to the public wa ter supply if possible. Local officials should

advise new residents who move to the area of the groundwater contamination and that

they should have their water supply tested before using groundwater for household

purposes.

 Residents should discontinue of use of a ny impacted private wells for household

purposes, including watering livestock and crops.

 CDPHE should continue to monitor the groundwater contaminant plume to assess

whether additional wells may be impacted in the future.

 CDPHE should conduct a water use survey in the affected ar ea to determine how

groundwater is being utilized by residents in Lincoln Park.

 CDPHE should evaluate the need for further an alysis of lead in soil should the areas

adjacent to the Cotter Mill property change current use patterns.

 ATSDR in the short-term, and CDPHE in th e long-term, should advise residents who

have fruit and vegetable gardens to wash the crops thoroughly before eating them. This

measure is just a precaution to remove soil adhering to the surface of the crop.

75Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## IX. PUBLIC HEALTH ACTION PLAN

The public health action plan for th e site contains a desc ription of actions that have been taken or

will be taken by ATSDR or other government agen cies at the site. The purpose of the public

health action plan is to ensu re that this document both iden tifies public health hazards and

provides a plan of action designed to mitigate and prevent harmful human health effects resulting

from exposure to the hazardous substances at this site.

Public health actions COMPLETED:

 ATSDR conducted site visits to gather comm unity health concerns, to communicate to

identified stakeholders, and to ga ther relevant si te-related data;

 ATSDR’s Exposure Investigations and Site Assessment Branch (EISB) performed two

Exposure Investigations to 1) evaluate blood le ad levels in children living in the Lincoln

Park area and 2) evaluate lead in dust in homes in the Lincoln Park area. (These

documents are available on our website at www.atsdr.cdc.gov .)

Public health actions PLANNED:

 ATSDR’s Health Promotion and Community Involvement Branch (HPCIB) will conduct

health-related educational activitie s in the community, as necessary.

 ATSDR’s HPCIB will coordinate community outreach and community involvement

activities for the site.

 ATSDR will continue to work with appropriate state and federal agencies and review, if

requested, additional relevant environmental data (including the water use survey) as it

becomes available.

 ATSDR will re-evaluate and revise the pub lic health action plan if needed. New

environmental, toxicological, health outcome data, or implementing the above proposed

actions may necessitate the need for additiona l or alternative actions at this site.

76Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## X. SITE TEAM

Teresa Foster, MPH

Environmental Health Scientist

Division of Health Assessment and Consultation

Site and Radiological Assessment Branch

Michael Brooks, CHP

Health Physicist

Division of Health Assessment and Consultation

Site and Radiological Assessment Branch

Debra Joseph, MHA

Community Involvement Specialist

Division of Health Assessment and Consultation

Health Promotion and Community Involvement Branch

Carla Galindo,* MPH

Health Education Specialist

Division of Health Assessment and Consultation

Health Promotion and Community Involvement Branch

Dawn Arlotta, MPH, CHES

Health Education Specialist

Division of Health Assessment and Consultation

Health Promotion and Community Involvement Branch

ATSDR Regional Representatives:

Chris Poulet

Environmental Health Scientist

Division of Regional Operations

David Dorian

Environmental Health Scientist

Division of Regional Operations

Epidemiological Review:

Candis Mayweather Hunter, MSPH

Epidemiologist

Division of Health Studies

*Carla Galindo provided health education input un til 2009. Carla is no longer employed at ATSDR.

77Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



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Colorado. November 16, 2006. Available at:

http://www.atsdr.cdc.gov/HAC/pha/Lin colnParkBloodLeadLevels/LincolnPark

BloodLeadLevelsChildrenHC11.16.06.pdf

.

[ATSDR] Agency for Toxic Substances and Disease Registry. 2006b. Health Consultation,

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http://www.atsdr.cdc.gov/HAC/pha/Linco lnParkDustinLeadinHomes/LincolnPark

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http://www.atsdr.cdc.gov/HAC/pha/Linco lnParkLeadinIndoo%20Dust/LincolnPark

LeadEI11.16.06.pdf

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.

[CDPHE 2001] Colorado Department of Public Health and the Environment. 2001. 6 CCR 1007

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# Appendix A - Tables

85Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 14. Well Use in Lincoln Park, 1989WellNumberDescriptionReported Well UsePersonalConsumptionIrrigatingFruitIrrigatingVegetableGardensWateringLivestockWateringLawns117Logan (LPWUS)119Birch (LPWUS)122Elm (LPWUS)123Cedar (LPWUS)124Elm (LPWUS)129Elm (LPWUS)130Poplar (LPWUS)138Field well, Cedar (LPWUS)139House well, Cedar (LPWUS)140C. R. Ransom house well, Cedar (LPWUS)144Cedar (LPWUS)165Spring, Elm (LPWUS)166Willow (LPWUS)168Grand (house well) (LPWUS)173Beulah (LPWUS)174Chestnut (LPWUS)189Hickory (LPWUS)198Grand (LPWUS)206Grand (field well) (LPWUS)212Cedar (LPWUS)219Locust (LPWUS)221Elm (LPWUS)222Elm (LPWUS)87WellNumberDescriptionReported Well UsePersonalConsumptionIrrigatingFruitIrrigatingVegetableGardensWateringLivestockWateringLawns223 Elm (LPWUS)224 Elm (LPWUS)226 Chestnut (LPWUS)229 Grand (LPWUS)230 Birch (LPWUS)231 Birch (LPWUS)235 Elm (LPWUS)237 Elm (LPWUS)239 Grand (LPWUS)241 Grand (LPWUS)243 Chestnut (LPWUS)245 Elm (LPWUS)246 Elm (LPWUS)252 Poplar (cistern* in barn) (LPWUS)255 Riley Dr. (LPWUS)261 Elm (LPWUS)262 Cedar (LPWUS)263 Willow (LPWUS)264 Chestnut (LPWUS)266 Willow (LPWUS)267 Willow (spring) (LPWUS)269 Birch273 Willow (cistern #1) (LPWUS)274 Grand (LPWUS)278 Cedar (LPWUS)Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment88WellNumberDescriptionReported Well UsePersonalConsumptionIrrigatingFruitIrrigatingVegetableGardensWateringLivestockWateringLawns280Grand (LPWUS)284Spring - Grand St. (LPWUS)285Grand (LPWUS)286Willow (cistern #2) (LPWUS)287Willow (LPWUS)288Poplar (cistern* on porch)293Cedar (LPWUS)Totals622201942Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentSource: IMS 1989*Modified from the original spelling: “cystern”Street numbers have been excluded for privacy reasons.LPWUS – Lincoln Park Water Use Survey89Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 15. Groundwater sampling data (chemicals) from wells used for personal consumptionChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV (mg/L)WellsSampledYearsSampledChlorideN/T*11/114.58.814Spring, Elm [165]13-Mar-84250(SecondaryMCL)165, 1681984, 2005–2007IronD2/120.040.060.1Grand (house well) [168]19-Aug-0526 (RBC)165, 1681984, 2004–2007ManganeseD2/120.0020.0080.01Grand (house well) [168]13-Dec-040.5 (RMEG,child)165, 1681984, 2004–2007MolybdenumD52/590.0070.0820.28Hickory [189]19-Jan-890.035 (SS);0.05 (RMEG,child)165, 168,189, 198,219, 2551984, 1988–1991, 1995,2000–2007NitrateT8/80.52.97.7Grand (house well) [168]19-Mar-0710 (MCL)1682005–2007SeleniumD0/2NDNDND-­-­0.05(c-EMEG,child)165, 1681984SulfateN/T*11/111562214Grand (house well) [168]19-Aug-05250(SecondaryMCL)165, 1681984, 2005–2007TotalDissolvedSolidsN/T*11/11240330410Spring, Elm [165]13-Mar-84500(SecondaryMCL)165, 1681984, 2005–2007UraniumD56/570.0010.0280.067Hickory [189]15-Dec-060.03 (MCL)165, 168,189, 198,219, 2551984, 1988–1991, 1995,2001–2007Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.The source of water used for personal consumption at 1935 Elm [165] was a spring.90Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment*For chloride, sulfate, and total dissolved solids, 1984 data were designated “N” and 2005–2007 data were designated “T”.c-EMEG – chronic environmental media evaluation guideN – not defined in the CDPHE databaseCV – comparison valueND – not detectedD – dissolvedRBC – risk based concentration for drinking waterLTHA – lifetime health advisory for drinking waterRMEG – reference dose media evaluation guideMCL – maximum contaminant levelSS – Colorado state groundwater standardmg/L – milligrams per literT – total91Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 16. Groundwater sampling data (chemicals) from background wellsChemicalTypeFrequencyof DetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)YearsSampledAluminumD0/25NDNDND-­10(c-EMEG, child)1981, 1988–1994AmmoniaN3/450.020.44.226-Jan-9030(LTHA)1988–1994AmmoniumT0/3NDNDND-­NA1995ChlorideN/T*168/168312110.307-Jan-80250(Secondary MCL)1975, 1976,1978–2007IronD24/790.020.030.316-May-8926(RBC)1981–2007ManganeseD13/790.0050.0070.0516-Mar-990.5(RMEG, child)1981–2007MolybdenumD116/1930.0050.0230.309-Nov-82,09-Jun-760.035 (SS);0.05 (RMEG, child)1975, 1976,1979–2007NitrateN/T*70/790.42.550.4**10-Feb-8910 (MCL)1988–2007SeleniumD10/1030.0010.0030.01515-Apr-800.05(c-EMEG, child)1975, 1977–1988, 1996–2000SulfateN/T*171/1711061434§18-Aug-80250(Secondary MCL)1975–2007Total Dissolved SolidsN/T*171/1712864291,580†18-Aug-80500(Secondary MCL)1980–2007UraniumD155/1930.0040.0210.2907-Aug-790.03 (MCL)1975–1977,1979–2007Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.The USGS identified Well 10 (1220 So. 12thSt.) and Well 114 (1408 Pine) as representative of background for the Lincoln Park area (Weston 1998).*For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.** Only two of 79 samples were above the CV.92Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment§Only one of 171 samples was above the CV.†The maximum concentration appears to be an outlier. The next highest concentration is 590 mg/L.c-EMEG – chronic environmental media evaluation guideNA – not availableCV – comparison valueND – not detectedD – dissolvedRBC – risk based concentration for drinking waterLTHA – lifetime health advisory for drinking waterRMEG – reference dose media evaluation guideMCL – maximum contaminant levelSS – Colorado state groundwater standardmg/L – milligrams per literT – totalN – not defined in the CDPHE database93Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 17. Groundwater sampling data (chemicals) from the Grand Avenue WellChemicalTypeFrequency ofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)Years SampledChlorideN/T*10/104.58.2501120-Jun-84,20-Jun-05250(Secondary MCL)1984, 2005–2007IronD2/110.040.060.119-Aug-0526(RBC)1984,2004–2007ManganeseD2/110.0020.0090.0113-Dec-040.5(RMEG, child)1984, 2004–2007MolybdenumD15/200.0080.010.01521-Jun-040.035 (SS);0.05(RMEG, child)1984, 1988–1991,2004–2007NitrateT8/80.52.97.719-Mar-0710(MCL)2005–2007SeleniumD0/1NDNDND-­0.05(c-EMEG, child)1984SulfateN/T*10/10155821419-Aug-05250(Secondary MCL)1984, 2005–2007Total DissolvedSolidsN/T*10/1024032240219-Mar-07500(Secondary MCL)1984, 2005–2007UraniumD20/200.0010.0130.021828-Mar-050.03(MCL)1984, 1988–1991,2004–2007Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.*For chloride, sulfate, and total dissolved solids, 1984 data were designated “N” and 2005–2007 data were designated “T”.c-EMEG – chronic environmental media evaluation guideND – not detectedCV – comparison valueRBC – risk based concentration for drinking waterD – dissolvedRMEG – reference dose media evaluation guideMCL – maximum contaminant levelSS – Colorado state groundwater standardmg/L – milligrams per literT – totalN – not defined in the CDPHE database94Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 18. Groundwater sampling data (chemicals) fromwells used to irrigate fruit and vegetable gardensChemicalTypeFrequencyofDetectionMinimum (mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV (mg/L)WellsSampledYearsSampledAluminumD3/1200.010.186*0.02Elm [124 ] &Elm[129]15-Mar-9510(c-EMEG,child)117, 119, 124,129, 130, 140,1441981, 1988–1995AmmoniaN10/530.010.30.6house well, Cedar[140]23-Aug-8830 (LTHA)119, 124, 129,130, 140, 1441988–1995AmmoniumT0/3NDNDND-­-­NA119, 140, 1441995CadmiumD0/3NDNDND-­-­0.002(c-EMEG,child)119, 140, 1441995ChlorideN/T**784/7932.519.6232house well, Cedar[140]05-Apr-79250(SecondaryMCL)117, 119, 124,129, 130, 140,144, 165, 174,2241970, 1975,1976, 1978–2007CopperD0/3NDNDND-­-­0.1 (i-EMEG,child)119, 140, 1441995IronD114/3980.0110.0290.31Elm [129]21-Apr-0326 (RBC)117, 119, 124,129, 130, 140,144, 165, 174,2241970, 1981–2007ManganeseD69/3970.00070.0080.13house well, Cedar[140]09-Sep-940.5(RMEG,child)117, 119, 124,129, 130, 140,144, 165, 174,2241981–2007MolybdenumD1,052/1,0770.0040.9942house well, Cedar[140]12-May-730.035 (SS);0.05(RMEG,child)All 28 wells(see Table 14)1968–2007NickelD0/3NDNDND-­-­0.2 (RMEG,child)119, 140, 144199595Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentChemicalTypeFrequencyofDetectionMinimum (mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV (mg/L)WellsSampledYearsSampledNitrateN/T**159/1850.11.79.8Cedar [144]14-May-7010 (MCL)119, 124, 129,130, 140, 144,174, 2241970, 1988–2007SeleniumD115/6260.0010.0030.082†house well, Cedar[140]21-Apr-780.05(c-EMEG,child)117, 119, 124,129, 130, 140,144, 165, 174,224, 2641974–1988,1995–2000SulfateN/T**798/800821425,460‡house well, Cedar[140]07-May-79250(SecondaryMCL)117, 119, 124,129, 130, 140,144, 165, 174,2241970, 1975–2007TotalDissolvedSolidsN/T**767/767315503,438house well, Cedar[140]20-Apr-81500(SecondaryMCL)117, 119, 124,129, 130, 140,144, 165, 174,2241970, 1980–2007UraniumD1,048/1,0880.00030.132.54house well, Cedar[140]house well, Cedar[140]05-Jan-790.03 (MCL)All 28 wells(see Table 14)1962–1964,1967, 1968,1971, 1974–2007S1/200.0810.005§0.08127-May-97140, 174, 2241995–2000VanadiumD0/3NDNDND-­-­0.03(i-EMEG,child)119, 140, 1441995ZincD2/30.0050.010.022Birch[119]25-Aug-953 (c-EMEG,child)119, 140, 1441995Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.The source of water used to water fruits and vegetable gardens at 1935 Elm [165] was a spring.96Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment*The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.†Only two of 626 samples were above the CV.‡The maximum concentration appears to be an outlier. The next highest concentration is 1,948 mg/L from the same well [140] in 1981.§The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.c-EMEG – chronic environmental media evaluation guideNA – not availableCV – comparison valueND – not detectedD – dissolvedRBC – risk based concentration for drinking wateri-EMEG – intermediate environmental media evaluation guideRMEG – reference dose media evaluation guideLTHA – lifetime health advisory for drinking waterS – suspendedMCL – maximum contaminant levelSS – Colorado state groundwater standardmg/L – milligrams per literT – totalN – not defined in the CDPHE database97Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 19. Groundwater sampling data (radionuclides) fromwells used to irrigate fruit and vegetable gardensRadionuclideTypeFrequencyofDetectionMinimum (pCi/L)Average(pCi/L)Maximum(pCi/L)Location ofMaximumDate ofMaximumCV(pCi/L)WellsSampledYearsSampledLead-210D29/29-0.20.221.5Birch [119]house well, Cedar[140]21-Jun-95NA119, 140, 144,174, 2241995–2000S20/20-0.10.150.622-Feb-96,05-May-99140, 174, 2241995–2000Polonium-210D29/29-0.10.130.6Cedar [144]house well, Cedar[140]08-Mar-95,21-Jun-95,NA119, 140, 144,174, 2241995–2000S20/2000.120.622-Feb-96,05-Dec-96140, 174, 2241995–2000Radium-226D29/2900.120.5house well, Cedar[140]-­12-May-955 (MCLradium226/228)119, 140, 144,174, 2241995–2000S19/19*000-­140, 174, 2241995–2000Thorium-230D28/28-0.10.080.3Birch [119]house well, Cedar[140]house well, Cedar[140]25-Aug-9521-Feb-95NA119, 140, 144,174, 2241995–2000S17/1700.080.305-May-99140, 174, 2241995–2000Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.*The detect flag is “Y” for all 19 samples, however, the result value is zero for all 19 samples.CV – comparison valueNA – not availableD – dissolvedpCi/L – picocuries per literMCL – maximum contaminant levelS – suspended98Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 20. Groundwater sampling data (chemicals) from wells used to water livestockChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV (mg/L)WellsSampledYearsSampledAluminumD0/19NDNDND-­-­10(c-EMEG, child)1441981, 1988–1995AmmoniaN0/10NDNDND-­-­30 (LTHA)1441988–1995AmmoniumT0/1NDNDND-­-­NA1441995CadmiumD0/1NDNDND-­-­0.002(c-EMEG, child)1441995ChlorideN/T*160/1602.514185Cedar [144]24-Aug-83250 (SecondaryMCL)144, 166, 168,1741970, 1975,1976, 1979–1989, 1991–2007CopperD0/1NDNDND-­-­0.1 (i-EMEG,child)1441995IronD27/970.030.040.19Cedar [144]18-Oct-0126 (RBC)144, 166, 168,1741970, 1981–2007ManganeseD14/960.00070.0070.02Cedar [144]13-Jul-81,13-Sep-83,17-May-01,06-Jun-02,23-Oct-030.5 (RMEG,child)144, 166, 168,1741981–2007MolybdenumD271/2860.0060.2121Cedar [144]12-May-710.035 (SS);0.05 (RMEG,child)All 19 wells(see Table 14)1968–1971,1975–1977,1979–2007NickelD0/1NDNDND-­-­0.2 (RMEG,child)144199599Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV (mg/L)WellsSampledYearsSampledNitrateN/T*55/580.11.89.8Cedar [144]14-May-7010(MCL)144, 168, 1741970, 1988–2007SeleniumD10/1190.0010.0030.011Cedar [144]19-Mar-800.05(c-EMEG, child)144, 166, 168,1741975–1977,1979–1988,1995–2000SulfateN/T*162/16210951,650**Cedar [144]18-Aug-80250 (SecondaryMCL)144, 166, 168,1741970, 1975–1977, 1979–1989, 1991–2007TotalDissolvedSolidsN/T*162/162195465860Cedar [144]18-Aug-80500 (SecondaryMCL)144, 166, 168,1741970, 1980–2007UraniumD283/3020.0010.0340.46Cedar [144]28-Jun-680.03 (MCL)All 19 wells(see Table 14)1962–1964,1967, 1968,1971, 1975–1977, 1979–2007S0/1NDNDND-­-­1741996VanadiumD0/1NDNDND-­-­0.03(i-EMEG, child)1441995ZincD0/1NDNDND-­-­3 (c-EMEG,child)1441995Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.** The maximum concentration appears to be an outlier. The next highest concentration is 340 mg/L from the same well [144] in 1984.100Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Commentc-EMEG – chronic environmental media evaluation guideCV – comparison valueD – dissolvedi-EMEG – intermediate environmental media evaluation guideLTHA – lifetime health advisory for drinking waterMCL – maximum contaminant levelmg/L – milligrams per literN – not defined in the CDPHE databaseND – not detectedRBC – risk based concentration for drinking waterRMEG – reference dose media evaluation guideS – suspendedSS – Colorado state groundwater standardT – total101Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 21. Groundwater sampling data (radionuclides) from wells used to water livestockRadionuclideTypeFrequencyofDetectionMinimum(pCi/L)Average(pCi/L)Maximum(pCi/L)Location ofMaximumDate ofMaximumCV (pCi/L)WellsSampledYearsSampledLead-210D4/4-0.10.10.3Cedar [144]Chestnut [174]08-Mar-95NA144, 1741995, 1996S1/10.20.20.219-Sep-961741996Polonium-210D4/4-0.10.30.6Cedar [144]Chestnut [174]08-Mar-95,21-Jun-95NA144, 1741995, 1996S1/1*00019-Sep-961741996Radium-226D4/40.10.10.1--**Chestnut [174]--**5 (MCLradium226/228)144, 1741995, 1996S1/1*00019-Sep-961741996Thorium-230D4/400.050.1Cedar [144]Chestnut [174]Chestnut [174]20-Sep-9519-Sep-96NA144, 1741995, 1996S1/1*00019-Sep-961741996Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.* The detect flag is “Y” for the one sample, however, the result value is zero.** All four result values were 0.1 pCi/L.CV – comparison valueD – dissolvedMCL – maximum contaminant levelNA – not availablepCi/L – picocuries per literS – suspended102Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 22. Groundwater sampling data (chemicals) from wells used to water lawnsChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV(mg/L)WellsSampledYearsSampledAluminumD11/2390.010.19*0.13Field well, Cedar [138]18-Dec-9010(c-EMEG,child)117, 119, 122,123, 124, 129,130, 138, 139,140, 1441981,1988–1995AmmoniaN21/1120.010.30.9Field well, Cedar [138]23-Aug-8830 (LTHA)119, 122, 123,124, 129, 130,138, 139, 140,1441988–1995AmmoniumT0/5NDNDND-­-­NA119, 138, 139,140, 1441995CadmiumD0/5NDNDND-­-­0.002(c-EMEG,child)119, 138, 139,140, 1441995ChlorideN/T**1,362/1,3722.530450Field well, Cedar [138]12-Aug-80250(SecondaryMCL)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,2241970, 1975,1976,1978–2007CopperD0/5NDNDND-­-­0.1(i-EMEG,child)119, 138, 139,140, 1441995IronD205/6830.0050.0310.31Field well, Cedar [138]Elm [129]09-Mar-9521-Apr-0326 (RBC)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,2241970,1981–2007103Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV(mg/L)WellsSampledYearsSampledManganeseD134/6830.00050.0080.13house well, Cedar [140]09-Sep-940.5(RMEG,child)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,2241979,1981–2007MolybdenumD1,755/1,7900.0042.256.7Field well, Cedar [138]11-Aug-720.035 (SS);0.05(RMEG,child)All 42 wells(see Table 14)1968–2007NickelD0/5NDNDND-­-­0.2 (RMEG,child)119, 138, 139,140, 1441995NitrateN/T**277/3140.11.89.8Cedar [144]14-May-7010 (MCL)119, 122, 123,124, 129, 130,138, 139, 140,144, 168, 174,2241970,1988–2007SeleniumD320/1,1050.0010.0050.134Field well, Cedar [138]13-Jul-810.05(c-EMEG,child)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,224, 2641974–1976,1978–1988,1995–2000SulfateN/T**1,382/1,384835125,460†house well, Cedar [140]07-May-79250(SecondaryMCL)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,2241970,1975–2007104Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentChemicalTypeFrequencyofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Location ofMaximumDate ofMaximumCV(mg/L)WellsSampledYearsSampledTotalDissolvedSolidsN/T**1,311/1,311317464,373Field well, Cedar [138]06-Mar-81500(SecondaryMCL)117, 119, 122,123, 124, 129,130, 138, 139,140, 144, 165,166, 168, 174,2241970,1980–2007UraniumD1,733/1,7890.00030.2335.161Field well, Cedar [138]01-Aug-680.03 (MCL)All 42 wells(see Table 14)1962–1964,1967, 1968,1971,1974–2007S4/380.00670.0100.26Field well, Cedar [138]27-May-97138, 140, 174,2241995–2000VanadiumD0/5NDNDND-­-­0.03(i-EMEG,child)119, 138, 139,140, 1441995ZincD3/50.0050.0070.022Birch[119]25-Aug-953 (c-EMEG,child)119, 138, 139,140, 1441995Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.†The maximum concentration and the second highest concentration(23,200 mg/L from Well 138 in 1978) appear to be outliers. Thethird highest concentration is 3,360 mg/Lfrom Well 138 in 1979.c-EMEG – chronic environmental media evaluation guideMCL – maximum contaminant levelRMEG – reference dose media evaluation guideCV – comparison valuemg/L – milligrams per literS – suspendedD – dissolvedN – not defined in the CDPHE databaseSS – Colorado state groundwater standardi-EMEG – intermediate environmental media evaluation guideND – not detectedT – totalLTHA – lifetime health advisory for drinking waterRBC – risk based concentration for drinking water105Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 23. Groundwater sampling data (radionuclides) from wells used to water lawnsRadionuclideTypeFrequencyofDetectionMinimum(pCi/L)Average(pCi/L)Maximum(pCi/L)Location ofMaximumDate ofMaximumCV(pCi/L)WellsSampledYearsSampledLead-210D53/53-0.20.21.5Birch [119]house well, Cedar [140]Field well, Cedar [138]21-Jun-95NA119, 138, 139,140, 144, 174, 2241995–2000S38/38-0.10.10.622-Feb-96,05-May-99138, 140, 174, 2241995–2000T1/1*00006-Sep-961381996Polonium-210D53/53-0.10.20.9Field well, Cedar [138]house well, Cedar [140]Field well, Cedar [138]04-May-99NA119, 138, 139,140, 144, 174, 2241995–2000S38/3800.10.622-Feb-96,05-Dec-96138, 140, 174, 2241995–2000T1/10.50.50.506-Sep-961381996Radium-226D51/5100.10.5house well, Cedar [140]Field well, Cedar [138]Field well, Cedar [138]12-May-955 (MCLradium226/228)119, 138, 139,140, 144, 174, 2241995–2000S37/37**00.0030.130-Oct-95138, 140, 174, 2241995–2000T2/200.050.106-Sep-961381995–1996Thorium-230D51/51-0.10.080.4Field well, Cedar [138]house well, Cedar [140]Field well, Cedar [138]06-Aug-98NA119, 138, 139,140, 144, 174, 2241995–2000S34/3400.060.305-May-99138, 140, 174, 2241995–2000T1/10.10.10.106-Sep-961381996Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.* The detect flag is “Y” for the one sample, however, the result value is zero.** For all but one sample, the result value is zero.CV – comparison valuepCi/L – picocuries per literD – dissolvedS – suspendedMCL – maximum contaminant levelT – totalNA – not available106Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 24. Groundwater sampling data (chemicals) from Well 138ChemicalTypeFrequency ofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)Years SampledAluminumD8/570.050.23*0.1318-Dec-9010(c-EMEG, child)1981, 1988–1995AmmoniaN10/420.020.290.923-Aug-8830(LTHA)1988–1995AmmoniumT0/1NDNDND-­NA1995CadmiumD0/1NDNDND-­0.002(c-EMEG, child)1995ChlorideN/T**199/1995.57045012-Aug-80250(Secondary MCL)1975, 1976,1978–2000CopperD0/1NDNDND-­0.1(i-EMEG, child)1995IronD21/1060.010.0250.3109-Mar-9526(RBC)1981–2000ManganeseD21/1070.010.008§0.0611-Jun-910.5(RMEG, child)1979, 1981–2000MolybdenumD253/2531.18.056.711-Aug-720.035 (SS);0.05(RMEG, child)1968–1973, 1975,1976, 1978–2000NickelD0/1NDNDND-­0.2(RMEG, child)1995NitrateN/T**59/620.72.34.111-Jun-9110(MCL)1988–2000SeleniumD102/1510.0010.0110.134†13-Jul-810.05(c-EMEG, child)1974–1976,1978–1988,1995–2000SulfateN/T**200/200711,05923,200‡01-Nov-78250(Secondary MCL)1975, 1976,1978–2000Total DissolvedSolidsN/T**202/2022901,5304,37306-Mar-81500(Secondary MCL)1980–2000107Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentChemicalTypeFrequency ofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)Years SampledUraniumD253/2530.00050.735.16101-Aug-680.03 (MCL)1968, 1974–1976,1978–2000S3/180.0070.0160.2627-May-971995–2000VanadiumD0/1NDNDND-­0.03(i-EMEG, child)1995ZincD0/1NDNDND-­3 (c-EMEG, child)1995Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.§The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.†Only three of 151 samples were above the CV.‡The maximum concentration appears to be an outlier. The next highest concentration is 3,360 mg/L in 1979.c-EMEG – chronic environmental media evaluation guideNA – not availableCV – comparison valueND – not detectedD – dissolvedRBC – risk based concentration for drinking wateri-EMEG – intermediate environmental media evaluation guideRMEG – reference dose media evaluation guideLTHA – lifetime health advisory for drinking waterS – suspendedMCL – maximum contaminant levelSS – Colorado state groundwater standardmg/L – milligrams per literT – totalN – not defined in the CDPHE database108Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 25. Groundwater sampling data (radionuclides) from Well 138RadionuclideTypeFrequency ofDetectionMinimum(pCi/L)Average(pCi/L)Maximum(pCi/L)Date of MaximumCV (pCi/L)Years SampledLead-210D21/21-0.20.221.103-Aug-9527-May-97, 06-Feb-98,29-Jul-99, 19-Oct-9906-Sep-96NA1995–2000S18/1800.080.21995–2000T1/1*0001996Polonium-210D21/2100.280.904-May-9928-Aug-0006-Sep-96NA1995–2000S18/1800.110.41995–2000T1/10.50.50.51996Radium-226D19/1900.130.421-Mar-9630-Oct-9506-Sep-965 (MCL radium226/228)1995–2000S18/1800.0060.11995–2000T2/200.050.11995, 1996Thorium-230D20/2000.070.406-Aug-9804-May-99, 29-Jul-9906-Sep-96NA1995–2000S17/1700.040.21995–2000T1/10.10.10.11996Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.*The detect flag is “Y” even though the result value is zero.CV – comparison valueD – dissolvedMCL – maximum contaminant levelNA – not availablepCi/L – picocuries per literS – suspendedT – total109Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 26. Surface soil sampling data (chemicals) from eight zones around the Cotter Mill and from Lincoln ParkChemicalZone AZone BZone CZone DZone EZone FZone GZone HLincolnParkCV (ppm)ArsenicRange (ppm)33–6919–3914–4210–4016–3817–6017–3319–8613–500.5 (CREG),20 (c-EMEG,child)Frequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (ppm)453025262835264231BerylliumRange (ppm)0.5–1.60.5–0.90.6–10.5–1.20.6–1.70.5–0.70.6–0.70.5–0.90.5–1.7100 (cEMEG, child)Frequency ofDetection9/1011/129/1210/106/88/84/47/872/73Average (ppm)0.80.70.70.60.70.60.70.60.7CadmiumRange (ppm)1.2–152.1–132.2–162.5–6.85.3–188.9–1101.6–204.4–510.5–510 (c-EMEG,child)Frequency ofDetection10/1012/1212/1210/108/88/84/48/868/73Average (ppm)6.96.46.44.19.836.57.921.11.4LeadRange (ppm)43–27045–24046–26047–130100–28068–80037–45061–1,40017–270400 (SSL)Frequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (ppm)13210411374173380201445120ManganeseRange (ppm)180–480320–630200–500110–750150–420140–400200–370210–770290–6403,000(RMEG ,child)Frequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (ppm)336422356391298268290439424SeleniumRange (ppm)5–7397–165NDNDND75–44300 (cEMEG, child)Frequency ofDetection5/101/122/121/100/80/80/41/87/73Average (ppm)4.2*5.5*4*2.8*NDNDND3.1*3.5*Source: Weston 1998Bolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.110Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentEach sample is a composite of four subsamples collected from the corners of a 10x10 square established near the center of the grid.The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.See Figure for a map of the sampling zones.*The calculated averages are lower than the minimum detected concentrations due to including 1⁄2 the detection limit in the calculation.c-EMEG – chronic environmental media evaluation guideCREG – cancer risk evaluation guideCV – comparison valueND – not detectedppm – parts per millionRMEG – reference dose media evaluation guideSSL – EPA’s soil screening level for residential areas111Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 27. Surface soil sampling data (radionuclides) from eight zones around the Cotter Mill and from Lincoln ParkRadionuclideZone AZone BZone CZone DZone EZone FZone GZone HLincolnParkCV (pCi/g)Lead-210Range (pCi/g)1.6–9.73.0–14.42.5–6.02.3–4.52.6–6.12.7–4.91.2–4.41.5–4.70.7–4.2NAFrequency ofDetection10/1012/1212/1210/108/88/84/48/858/58Average (pCi/g)6.38.24.13.44.43.92.92.62.1Radium-226Range (pCi/g)2.4–10.73.6–16.51.3–5.71.4–2.32.5–5.61.9–3.01.4–1.91.2–2.21.1–2.25 (UMTRCA,surface)Frequency ofDetection10/1012/1212/1210/108/88/84/48/858/58Average (pCi/g)6.69.22.61.83.92.51.71.51.5Thorium-230Range (pCi/g)3.6–35.35.8–40.11.6–21.71.8–4.44.3–12.13.6–8.31.7–2.81.6–11.91.0–4.2NAFrequency ofDetection10/1012/1212/1210/108/88/84/48/858/58Average (pCi/g)17.720.95.92.57.75.22.43.31.7Uranium,naturalRange (pCi/g)0.871–4.2881.541–5.4270.737–5.6280.737–1.641.005–2.4120.6432–1.9430.5561–1.0050.536–1.2060.6566–3.417NAFrequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (pCi/g)2.453.291.981.171.521.210.830.731.215Uranium-234Range (pCi/g)0.436–2.140.771–2.710.369–2.810.369–0.820.503–1.210.322–0.9720.278–0.5030.268–0.6030.328–1.709NAFrequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (pCi/g)1.231.650.9910.5840.7580.6060.4130.3660.607112Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentRadionuclideZone AZone BZone CZone DZone EZone FZone GZone HLincolnParkCV (pCi/g)Uranium-238Range (pCi/g)0.436–2.140.771–2.710.369–2.810.369–0.820.503–1.210.322–0.9720.278–0.5030.268–0.6030.328–1.709NAFrequency ofDetection10/1012/1212/1210/108/88/84/48/873/73Average (pCi/g)1.231.650.9910.5840.7580.6060.4130.3660.607Source: Weston 1998Bolded textindicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide.The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.Each sample is a composite of four subsamples collected from the corners of a 10x10 square established near the center of the grid.See Figure for a map of the sampling zones.CV – comparison valueNA – not availablepCi/g – picocuries per gramUMTRCA – 1978 Uranium Mill Tailings Radiation Control Act113Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 28. Surface soil sampling data (rad ionuclides) from the county road and

the Cotter Uranium Mill access road

Radionuclide Samples from

background areas Samples along the

county road Samples along the

access road* CV

Radium-226 Range (pCi/g) 0.8–2.1 3.8– 14 2.7– 351 5 pCi/g

(UMTRCA,

surface) Frequency of Detection 5/5 5/5 6/6

Average (pCi/g) 1.42 7.7 65

Thorium-230 Range (pCi/g) 0.2–2.4 9.7–25 10–395

NA Frequency of Detection 3/5 5/5 6/6

Average (pCi/g) 1.53 20 87

Uranium,

natural Range (ppm) 1.18–3.05 5.28–29.2 4.31– 922 100 ppm

(i-EMEG, child

for highly

soluble salts) Frequency of Detection 5/5 5/5 6/6

Average (ppm) 1.87 13.6 161

Uranium-238** Range (pCi/g) 0.39–1.01 1.74–9.64 1.42–304

NA Frequency of Detection 5/5 5/5 6/6

Average (pCi/g) 0.62 4.5 53

Gamma

Exposure

Rates Range ( μ R/hr) NA 13.8–55.3 18.6–893

NA Frequency of Detection NA NA NA

Average ( μ R/hr) 15.7 25.8 73.7

Source: MFG 2005

Bolded text indicates that the average and/or maximum concentration exceeded the comparison value.

Each sample consists of 10 aliquots taken from 0–6 inches within a 100 m 2 area.

See Figure for a map of the sampling locations.

*There is limited potential for exposure to contaminants alon g the access road since access to the Cotter Mill is restricted an d soils

along the access road were re mediated in 2007 and 2008.

**Uranium-238 concentrations were calculated by multip lying the natural uranium concentrations by 0.33.

CV – comparison value

i-EMEG – intermediate environmental media evaluation guide

μR/hr – microroentgen per hour

NA – not available

pCi/g – picocuries per gram

ppm – parts per million

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act

114Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 29. Soil data (chemicals) fromsamples taken by CDPHE, January 2003ChemicalFrequency ofDetectionMinimum(ppm)Average(ppm)Maximum(ppm)Location of MaximumCV (ppm)Lead20/20234103,651*Private barn in Lincoln Park (dustsample)400 (SSL)Molybdenum0/20ND**ND**ND**-­300 (RMEG , child)Uranium20/201.26.031Mill Entrance Road100 (i-EMEG, child forhighly soluble salts)Source: CDPHE 2003, 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.See Figure for a map of the sampling locations.The sampling event was intentionally biased toward finding the highest amounts of contamination possible (CDPHE 2003).*The second highest lead concentration is 908 ppm from a location northwest of the Cotter Mill.**The molybdenum detection limit was 25 ppm.§Concentrations from the background location on the corner of Orchard Avenue and High Street were not included in the table.CV – comparison valuei-EMEG – intermediate environmental media evaluation guideND – not detectedppm – parts per millionRMEG – reference dose media evaluation guideSSL – EPA’s soil screening level for residential areasConcentrations from theBackground Location§Lead 36ppmMolybdenum NDUranium1.3 ppm115Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 30. Soil data (radionuclides) fromsamples taken by CDPHE, January 2003RadionuclideFrequency ofDetectionMinimum(pCi/g)Average(pCi/g)Maximum(pCi/g)Location of MaximumCV (pCi/g)Cesium-13720/2000.641.33Private residence in LincolnPark (dust sample)NALead-21020/201.99.722.8East of the Cotter MillNAPlutonium-239, 2409/200.030.03*0.06East of the Cotter Mill &a private residence in LincolnPark (dust sample)NAPotassium-4020/2017.622.631.9East of the Cotter MillNARadium-22620/201.47.821.2East of the Cotter Mill15 (UMTRCA, subsurface)Radium-22820/200.61.01.3Private barn in Lincoln Park(dust sample), private residencein Lincoln Park (dust sample),Pine St near Elm Ave in LincolnPark (sediment sample),Northwest of the Cotter Mill15 (UMTRCA, subsurface)Source: CDPHE 2003, 2007bBolded textindicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.See Figure for a map of the sampling locations.The sampling event was intentionally biased toward finding the highest amounts of contamination possible (CDPHE 2003).*The calculated average is the same as the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.** Concentrations from the background location on the corner of Orchard Avenue and High Street were not included in the table.CV – comparison valueNA – not availablepCi/g – picocuries per gramUMTRCA – 1978 Uranium Mill Tailings Radiation Control ActConcentrations from theBackground Location**Cesium-137 0.2 pCi/gLead-210 3.2pCi/gPlutonium-239, 240 NDPotassium-40 19.5 pCi/gRadium-226 1.9 pCi/gRadium-228 1.0 pCi/g116Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 31. Surface soil sampling datafrom 10 air monitoring locationsChemicalFrequencyof DetectionMinimum(ppm)Average(ppm)Maximum(ppm)Location of MaximumDate ofMaximumYearsSampledCV (ppm)Molybdenum106/1340.615.1251.3AS-204 (West Boundary)20021992–2006*300 (RMEG, child)RadionuclideFrequencyof DetectionMinimum(pCi/g)Average(pCi/g)Maximum(pCi/g)Location of MaximumDate ofMaximumYearsSampledCV (pCi/g)Radium-224**10/10-5.7-2.90.3Lincoln Park200620065 (UMTRCA, surface)Radium-226246/251<0.53.953.5AS-209 (Mill Entrance Road)20021979–2006†5 (UMTRCA, surface)Thorium-230107/1070.422.2354AS-209 (Mill Entrance Road)20021996–2006NAThorium-23260/600.51.47.9AS-209 (Mill Entrance Road)20022001–2006NAUranium258/262<0.0014.673.6AS-209 (Mill Entrance Road)20021979–2006NASource: Cotter 2007; GeoTrans 1986Bolded textindicates that the average and/or maximumconcentration exceededthe comparison value.Uranium and radium-226 were also tested in soil from two additional off-site locations (Oro Verde #1 and Oro Verde #2) in 1983and 1984.See Figure for a map of the air monitoring locations.*Data from 2006 are unavailable.**Data are blank corrected.†Results from 2005 were not reported based on quality assurance analysis (Cotter 2007).CV – comparison valueNA – not availablepCi/g – picocuries per gramppm – parts per millionRMEG – reference dose media evaluation guideUMTRCA – 1978 Uranium Mill Tailings Radiation Control Act117Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 32. Soil sampling data (chemicals) from location AS-212 (the Nearest Resident)ChemicalFrequency ofDetectionMinimum(ppm)Average(ppm)Maximum(ppm)Date ofMaximumYears SampledCV (ppm)Lead1/119919919915-Jan-032003400(SSL)Molybdenum7/81.611.342.420051999–2005300 (RMEG , child)Uranium1/14.94.94.915-Jan-032003100 (i-EMEG, child forhighly soluble salts)Source: CDPHE 2007b, Cotter 2007Averages were calculated using 1⁄2 the reporting detection limit for non-detects.See Figure for the location ofAS-212, the nearest resident.CV – comparison valuei-EMEG – intermediate environmental media evaluation guideppm – parts per millionRMEG – reference dose media evaluation guideSSL – EPA’s soil screening level for residential areas118Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 33. Soil sampling data (radionuclides)from location AS-212 (the Nearest Resident)RadionuclideFrequency ofDetectionMinimum(pCi/g)Average(pCi/g)Maximum(pCi/g)Date ofMaximumYears SampledCV (pCi/g)Cesium-1371/10.610.610.6115-Jan-032003NALead-2101/188815-Jan-032003NAPlutonium-239,2401/10.030.030.0315-Jan-032003NAPotassium-401/117.717.717.715-Jan-032003NARadium-224*1/1-3.6-3.6-3.6200620065(UMTRCA,surface)Radium-2268/81.43.37.520041999–2004, 20065 (UMTRCA, surface)Radium-2281/10.90.90.915-Jan-0320035(UMTRCA,surface)Thorium-2308/83.310.12020041999–2006NAThorium-2326/60.71.01.12001,20022001–2006NAUranium8/82.05.21320041999–2006NASource: CDPHE 2007b, Cotter 2007Bolded textindicates that the average and/or maximum concentration exceeded the comparison value for that radionuclide.See Figure for the location ofAS-212, the nearest resident.*Data are blank corrected.CV – comparison valueNA – not availablepCi/g – picocuries per gramUMTRCA – 1978 Uranium Mill Tailings Radiation Control Act119Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 34. Surface soil sampling data (chemicals) from lawns and gardens in Lincoln ParkChemicalFrequency ofDetectionMinimum(ppm)Average(ppm)Maximum(ppm)Location ofMaximumYears SampledCV (ppm)Arsenic15/15314450garden soil19960.5 (CREG),20 (c-EMEG, child)Beryllium14/150.50.71.1lawn soil1996100 (c-EMEG, child)Cadmium14/150.51.21.9lawn soil199610 (c-EMEG, child)Manganese15/15290428640lawn soil19963,000 (RMEG , child)Selenium1/32181.7*18garden soil1990, 1996300 (c-EMEG, child)Source: Weston 1996 (some or all of these data may also be included in Table)Bolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.c-EMEG – chronic environmental media evaluation guideCV – comparison valueppm – parts per millionRMEG – reference dose media evaluation guide120Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 35. Surface soil sampling data (radionuclides) from yards, gardens, and air monitoring locations in Lincoln ParkRadionuclideFrequency ofDetectionMinimum(pCi/g)Average(pCi/g)Maximum(pCi/g)Source of MaximumYears SampledCV (pCi/g)Lead-21017/170.41.62.50–2”gardensample1990NAPolonium-21017/171.11.72.60–2”gardensample1990NARadium-22619/190.81.52.00–2” garden sample1987, 1988, 19905 (UMTRCA, surface)Thorium-22817/171.01.41.80–2”gardensample1990NAThorium-23017/171.01.52.30–2”gardensample1990NAUranium-23429/290.3551.231.95Soil from the yard of aparticipant in the LPWUS1987–1990NAUranium-2350/17ND*ND*ND*-­1990NAUranium-23829/290.3551.211.95Soil from the yard of aparticipant in the LPWUS1987–1990NASource: Weston 1996*The uranium-235 detection limit was 0.2 pCi/g.CV – comparison valueLPWUS – Lincoln Park Water Use SurveyNA – not availableND – not detectedpCi/g – picocuries per gramUMTRCA – 1978 Uranium Mill Tailings Radiation Control Act121Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 36. Surface soil data (chemicals) from lawns and gardens in Lincoln Park

Chemical Samples from locations

irrigated with

contaminated well water Samples from locations

not irrigated with

contaminated well water CV (ppm)

Arsenic Range (ppm) 14– 50 13– 38 0.5 (CREG),

20 (c-EMEG, child) Frequency of Detection 26/26 47/47

Average (ppm) 36* 28*

Beryllium Range (ppm) 0.5–1.1 0.6–1.7

100 (c-EMEG, child) Frequency of Detection 25/26 47/47

Average (ppm) 0.7 0.8

Cadmium Range (ppm) 0.6–1.9 0.5–5

10 (c-EMEG, child) Frequency of Detection 23/26 45/47

Average (ppm) 1.2 1.5**

Lead Range (ppm) 17–270 †



### 400 (SSL) Frequency of Detection 73/73 †



### Average (ppm) 122 121

Manganese Range (ppm) 290–640 320–580

3,000

(RMEG , child) Frequency of Detection 26/26 47/47

Average (ppm) 430 421**

Molybdenum Range (ppm) Data not available § 

### Data not available §



### 300 (RMEG , child) Frequency of Detection Data not available § 

### Data not available §



### Average (ppm) 1.7* 0.5*

Selenium Range (ppm) 18 5–44

300 (c-EMEG, child) Frequency of Detection 1/26 6/47

Average (ppm) 3.1 3.8

Uranium Range (ppm) Data not available § 

### Data not available § 

### 100 (i-EMEG, child

for highly soluble

salts) Frequency of Detection Data not available § 

### Data not available §



### Average (ppm) 2.3* 1.6*

Source: Weston 1998

Bolded text indicates that the average and/or maximum concentration exc eeded the comparison va lue for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.

*The concentrations were statistical ly higher in irrigated soil samples.

**The calculated averages for cadmium and manganese differ slig htly from the reported mean concentrations in Table 3-3.

† The raw data for lead are not presented by whether the samples were taken from locati ons irrigated with contaminated well water

. However, Table 3-3 presents the mean concentrations by manner of irrigation.

§ The raw data for molybdenum and uranium are not presented in the report. Therefore, the range and frequency of detection could not

be determined. Table 3-3 presents the mean concentrations.

c-EMEG – chronic environmental media evaluation guide ppm – parts per million

CREG – cancer risk evaluation guide RMEG – reference dose media evaluation guide

CV – comparison value SSL – EPA’s soil screening level for residential areas

i-EMEG – intermediate environmental media evaluation guide

122Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 37. Surface soil data (radionuclides) from lawns and gardens in Lincoln Park

Radionuclide Samples from locations

irrigated with

contaminated well water Samples from locations

not irrigated with

contaminated well water CV (pCi/g)

Lead-210 Range (pCi/g) 0.8–3.0 0.7–4.2

NA Frequency of Detection 11/11 47/47

Average (pCi/g) 2.2 2.1*

Radium-226 Range (pCi/g) 1.3–1.7 1.1–2.2 5 (UMTRCA,

surface) Frequency of Detection 11/11 47/47

Average (pCi/g) 1.4 1.5

Thorium-230 Range (pCi/g) 1.1–2.2 1.0–4.2

NA Frequency of Detection 11/11 47/47

Average (pCi/g) 1.6* 1.7

Uranium, natural Range (pCi/g) 0.871–3.417 0.6566–2.077

NA Frequency of Detection 26/26 47/47

Average (pCi/g) 1.514 1.05

Uranium-234 Range (pCi/g) 0.436–1.709 0.328–1.039

NA Frequency of Detection 26/26 47/47

Average (pCi/g) 0.755 0.525

Uranium-238 Range (pCi/g) 0.436–1.709 0.328–1.039

NA Frequency of Detection 26/26 47/47

Average (pCi/g) 0.755 0.525

Source: Weston 1998

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.

*The calculated averages for lead-210 and thorium-230 differ slightly from the reported mean concentrations in Table 3-3.

CV – comparison value

NA – not available

pCi/g – picocuries per gram

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act

123Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 38. Sediment sampling data (chemicals) from Sand Creek

Chemical Location Concentration (ppm)

CV (ppm)

SD01 SD02* SD04

SD05

1 2 3

Arsenic NA 13.7 13 NA 17 <5 20 (c-EMEG, child)

Cadmium NA 3.9 7.2 NA 7.6 1.5 10 (c-EMEG, child)

Cobalt NA 11.3 43 NA 21 10 500 (i-EMEG, child)

Copper 19 52.3 46 NA 38 19 500 (i-EMEG, child)

Lead 27 106 93 NA 130 22 400 (SSL)

Molybdenum 4.4 2.6 8 NA 7.9 9.4 300 (RMEG , child)

Nickel NA 17 63 NA 28 18 1,000 (RMEG, child)

Zinc NA 343 540 NA 580 106 20,000 (c-EMEG, child)

Source: GeoTrans 1986

SD01 – mouth near the Arkansas River

SD02 – near spring where flow begins (reflects migration of contaminants in the groundwater)

SD04 – below the SCS Dam in

(1) an abandoned stock watering pond (formed by diversion of runoff water into a depression adjacent to Sand Creek)

(2) in drainage (reflects historical picture of uncontrolled emissions)

(3) in drainage above #2 (reflects historical picture of uncontrolled emissions)

SD05 – above the SCS Dam adjacent to the west property edge

Bolded text indicates that the concentr ation exceeded the comparison value for that chemical.

Samples were collected July 10–20, 1985.

*Values are the mean of three field replicates.

c-EMEG – chronic environmental media evaluation guide

CREG – cancer risk evaluation guide

CV – comparison value

i-EMEG – intermediate environmental media evaluation guide

ppm – parts per million

RMEG – reference dose media evaluation guide

SSL – EPA’s soil screening level for residential areas

124Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 39. Sediment sampling data (radionuclides) from Sand Creek

Radionuclide Location Average (pCi/g)

CV

SD01 SD02 SD04

SD05

1 2 3

Gross Alpha 22±3 47±9 240±40 74±9 39±7 22±5 NA

Gross Beta 29±6 43±8 90±20 34±7 32±7 32±6 NA

Radium-226 1.21±0.06 1.7±1 12.8 ± 0.6 3.5±0.2 3.4±0.2 2.3±1 5 (UMTRCA,

surface)

Throium-230 4.6±0.3 34±2 82±4 32±2 15.5±0.8 5.2±0.3 NA

Total Uranium 2.4 4.3 11.7 3.4 3.4 3.9 NA

Source: GeoTrans 1986

SD01 – mouth near the Arkansas River

SD02 – near spring where flow begins (reflects migration of contaminants in the groundwater)

SD04 – below the SCS Dam in

(1) an abandoned stock watering pond (formed by diversion of runoff water into a depression adjacent to Sand Creek)

(2) in drainage (reflects historical picture of uncontrolled emissions)

(3) in drainage above #2 (reflects historical picture of uncontrolled emissions)

SD05 – above the SCS Dam adjacent to the west property edge

Bolded text indicates that the concentration exceeded the comparison value for that radionuclide.

Samples were collected July 10–20, 1985.

CV – comparison value

NA – not available

pCi/g – picocuries per gram

UMTRCA – 1978 Uranium Mill Tailings Radiation Control Act

125Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 40. Chemical sampling for the Sand Creek Cleanup Project

Chemical Frequency of

Detection Minimum

(ppm) Average

(ppm) Maximum

(ppm) CV (ppm)

Arsenic 7/7 2.7 3.9 6.9 20 (c-EMEG, child)

Barium 7/7 69 106 160 10,000 (c-EMEG, child)

Beryllium 7/7 0.2 0.3 0.6 100 (c-EMEG, child)

Chromium 7/7 7.4 9.5 12.8 200 (RMEG, child for

hexavalent chromium)

Lead 7/7 17 35 75 400 (SSL)

Manganese 7/7 258 343 502 3,000 (RMEG , child)

Molybdenum 7/7 2.1 2.8 3.5 300 (RMEG

, child)

Nickel 7/7 8 10.9 16 1,000 (RMEG , child)

Selenium 0/7 ND* ND* ND* 300 (c-EMEG, child)

Vanadium 7/7 16.1 20.3 26.1 200 (i-EMEG, child)

Source: Cotter 2000

Bolded text indicates that the average and/or maximum concentration exc eeded the comparison va lue for that chemical.

Samples were collected in April and May 1998.

*The selenium detection limit was 5 ppm.

c-EMEG – chronic environmental media evaluation guide

CREG – cancer risk evaluation guide

CV – comparison value

i-EMEG – intermediate environmental media evaluation guide

ND – not detected

ppm – parts per million

RMEG – reference dose media evaluation guide

SSL – EPA’s soil screening level for residential areas

126Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 41. Surface water sampling data (chemicals) from Sand CreekChemicalTypeFrequency ofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)YearsSampledAluminumD0/2NDNDND-­10 (c-EMEG, child)1988AmmoniaN2/350.50.43*0.810-Nov-8830(LTHA)1988–1994AmmoniumT0/3NDNDND-­NA1995ChlorideN/T**92/92381413-May-04250 (Secondary MCL)1986–2007IronD21/550.030.040.2607-Nov-0226(RBC)1986–1988,1995–2007ManganeseD36/550.00840.041.3†19-Nov-010.5 (RMEG, child)1986–1988,1995–2007MolybdenumD98/1040.0050.020.051†01-Dec-870.035 (SS);0.05 (RMEG, child)1986–2007NitrateN/T**75/870.51.14.703-May-0610(MCL)1988–2007SeleniumD0/8NDNDND-­0.05 (c-EMEG, child)1986–1988SulfateN/T**94/941265310†11-Oct-96250 (Secondary MCL)1986–2007Total Dissolved SolidsN/T**99/9910.73691,372‡22-Aug-91500 (Secondary MCL)1986–2007UraniumD101/1010.0060.0120.026701-Aug-950.03 (MCL)1986–2007S8/480.0000980.0010.003110-Jan-001995–2007Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.†Only the maximum concentration was above the CV.‡This appears to be an outlier. The next highest concentration is 460 mg/L. Only the maximum concentration was above the CV.c-EMEG – chronic environmental media evaluation guidemg/L – milligrams per literRBC – risk based concentration for drinking waterCV – comparison valueN – not defined in the CDPHE databaseRMEG – reference dose media evaluation guideD – dissolvedNA – not availableS – suspendedLTHA – lifetime health advisory for drinking waterND – not detectedSS – Colorado state groundwater standardMCL – maximum contaminant levelT – total127Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 42. Surface water sampling data (radionuclides) from Sand CreekRadionuclideTypeFrequency ofDetectionMinimum(pCi/L)Average(pCi/L)Maximum(pCi/L)Date of MaximumCV (pCi/L)Years SampledLead-210D40/49-0.20.393.706-Aug-0706-Aug-07NA1995–20071995–2007S40/49-0.10.404.6Polonium-210D41/49-0.10.150.628-Nov-0609-Nov-99NA1995–20071995–2007S40/4900.131.6Radium-226D45/4900.120.603-May-0609-Nov-99,28-Nov-065 (MCL radium226/228)1995–20071995–2007S42/4700.060.4Thorium-230D44/49-0.10.130.828-Nov-0606-Aug-07NA1995–20071995–2007S41/4600.160.9Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.CV – comparison valueD – dissolvedMCL – maximum contaminant levelNA – not availablepCi/L – picocuries per literS – suspended128Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 43. Surface water sampling data (chemicals) from the DeWeese Dye DitchChemicalTypeFrequency ofDetectionMinimum(mg/L)Average(mg/L)Maximum(mg/L)Date ofMaximumCV (mg/L)YearsSampledAluminumD1/40.020.06*0.0214-Jun-9510 (c-EMEG, child)1981, 1995AmmoniaN0/2NDNDND-­30(LTHA)1989,1995ChlorideN/T**95/102271808-May-01250 (Secondary MCL)1981–1989,1995–2007IronD22/500.0290.943†09-Jun-9926 (RBC)1981–1987,1995–2007ManganeseD28/500.0040.051.9‡09-Jun-990.5 (RMEG, child)1981–1987,1995–2007MolybdenumD10/1200.0010.013§0.01306-Aug-030.035 (SS);0.05 (RMEG, child)1981–2007NitrateN/T**7/260.10.30.810-May-00,02-Aug-0610 (MCL)1989,1995–2007SeleniumD4/760.0050.003††0.01122-Jun-87,25-Apr-880.05 (c-EMEG, child)1981–1988,1995SulfateN/T**102/1026319528-Apr-82250 (Secondary MCL)1981–1989,1995–2007Total Dissolved SolidsN/T**119/11912.92311,647‡‡10-Sep-90500 (Secondary MCL)1981–2007UraniumD86/1160.00040.010.11§§05-May-830.03 (MCL)1981–2007S0/8NDNDND-­1996–1999Source: CDPHE 2007bBolded textindicates that the average and/ormaximum concentration exceeded the comparison value for that chemical.Averages were calculated using 1⁄2 the reporting detection limit for non-detects.*The calculated average is higher than the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.** For chloride, nitrate, sulfate, and total dissolved solids, pre-1995 data were designated “N” and post-1995 data were designated “T”.†This appears to be an outlier. The next highest concentration is 0.24 mg/L from the same location in 2003. Only the maximum concentration was above the CV.‡Only the maximum concentration was above the CV.§The calculated average is the same as the maximum detected concentration due to including 1⁄2 the detection limit in the calculation.129Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment††The calculated average is the lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calculation.‡‡This appears to be an outlier. The next highest concentrationis 870 mg/L. Only three of the 119 samples were above the CV.§§Only three of the samples were above the CV.c-EMEG – chronic environmental media evaluation guideCV – comparison valueD – dissolvedLTHA – lifetime health advisory for drinking waterMCL – maximum contaminant levelmg/L – milligrams per literN – not defined in the CDPHE databaseND – not detectedRBC – risk based concentration for drinking waterRMEG – reference dose media evaluation guideS – suspendedSS – Colorado state groundwater standardT – total130Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 44. Surface water sampling data (radionuclides) from the DeWeese Dye DitchRadionuclideTypeFrequency ofDetectionMinimum(pCi/L)Average(pCi/L)Maximum(pCi/L)Date of MaximumCV (pCi/L)Years SampledLead-210D8/800.31.209-May-9612-May-97NA1996–19991996–1999S8/800.090.2Polonium-210D8/800.10.209-Jun-99, 02-Sep­9909-Jun-99NA1996–19991996–1999S8/800.050.2Radium-226D8/800.040.109-May-96,16-Jul-96, 02-Sep-9902-Sep-995 (MCL radium226/228)1996–19991996–1999S7/700.010.1Thorium-230D8/800.0250.212-May-9709-Sep-98NA1996–19991996–1999S7/700.070.2Source: CDPHE 2007bAverages were calculated using 1⁄2 the reporting detection limit for non-detects.Negative and zero result values were included in the summary statistics.CV – comparison valueD – dissolvedMCL – maximum contaminant levelNA – not availablepCi/L – picocuries per literS – suspended131Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 45. Surface water sampling data (chemicals) from the Arkansas River

Chemical Type Upstream of

Sand Creek at

1 st 

### Street (907) Downstream of

Sand Creek at

Mackenzie Ave (904) CV (mg/L)

Chloride T Range (mg/L) 3–60 3–14

250 (Secondary MCL) Frequency of Detection 127/130 127/130

Average (mg/L) 8 8

Molybdenum D Range (mg/L) 0.0029– 0.046 0.003–0.029 0.035 (SS);

0.05 (RMEG, child) Frequency of Detection 32/142 46/142

Average (mg/L) 0.025 0.025

Molybdenum S Range (mg/L) 0.0019–0.022 0.0017–0.016 0.035 (SS);

0.05 (RMEG, child) Frequency of Detection 8/135 6/135

Average (mg/L) 0.025 0.025

Molybdenum T Range (mg/L) 0.006 0.005 0.035 (SS);

0.05 (RMEG, child) Frequency of Detection 1/7 1/7

Average (mg/L) 0.003* 0.003*

Sulfate T Range (mg/L) 10– 1,300** 5– 4,200 **

250 (Secondary MCL) Frequency of Detection 130/130 130/130

Average (mg/L) 41 84

Total

Dissolved

Solids T Range (mg/L) 45– 2,880 † 

### 62–337

500 (Secondary MCL) Frequency of Detection 130/130 130/130

Average (mg/L) 172 192

Uranium D Range (mg/L) 0.0003– 0.0135 0.0002–0.0155

0.03 (MCL) Frequency of Detection 129/130 130/130

Average (mg/L) 0.004 0.005

Uranium S Range (mg/L) 0.0002– 0.014 0.0002–0.0043

0.03 (MCL) Frequency of Detection 16/121 14/121

Average (mg/L) 0.001 0.001

Uranium T Range (mg/L) 0.0033–0.0056 0.0029–0.0054

0.03 (MCL) Frequency of Detection 7/7 7/7

Average (mg/L) 0.004 0.004

Source: CDPHE 2007b

Bolded text indicates that the average and/or maximum concentration exc eeded the comparison va lue for that chemical.

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

All samples were collected between 1995 and 2007. The “T” samples for uranium were only collected in 1995.

* The calculated average is lower than the minimum detected concentration due to including 1⁄2 the detection limit in the calcula tion.

** This appears to be an outlier. The next highest concentrati on is 200 mg/L. Only the maximum concentration was above the CV.

† This appears to be an outlier. The next highest concentration is 405 mg/L. Only the maximum concentration was above the CV.

CV – comparison value mg/L – milligrams per liter SS – Colorado state

D – dissolved RMEG – reference dose media evaluation guide groundwater standard

MCL – maximum contaminant level S – suspended T – total

132Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 46. Surface water sampling data (r adionuclides) from the Arkansas River

Radionuclide Type Upstream of

Sand Creek at

1 st 

### Street (907) Downstream of

Sand Creek at

Mackenzie Ave (904) CV (pCi/L)

Lead-210 D Range (pCi/L) ND 3.7

NA Frequency of Detection 0/1 1/1

Average (pCi/L) ND 3.7

Lead-210 S Range (pCi/L) ND 0

NA Frequency of Detection 0/1 1/2

Average (pCi/L) ND 0.25*

Polonium-210 D Range (pCi/L) ND ND

NA Frequency of Detection 0/1 0/1

Average (pCi/L) ND ND

Polonium-210 S Range (pCi/L) ND 0.26–3.3

NA Frequency of Detection 0/1 2/2

Average (pCi/L) ND 1.8

Radium-226 D Range (pCi/L) 0–0.6 0–0.4 5 (MCL radium226/228) Frequency of Detection 119/128 116/127

Average (pCi/L) 0.13 0.07

Radium-226 S Range (pCi/L) 0–0.8 0–2.3 5 (MCL radium226/228) Frequency of Detection 114/120 112/119

Average (pCi/L) 0.08 0.09

Radium-226 T Range (pCi/L) 0.1–0.7 0.1–0.7 5 (MCL radium226/228) Frequency of Detection 7/7 7/7

Average (pCi/L) 0.3 0.3

Thorium-230 D Range (pCi/L) -0.1–1 -0.1–1.2

NA Frequency of Detection 121/127 116/127

Average (pCi/L) 0.1 0.1

Thorium-230 S Range (pCi/L) 0–2.5 0–2.4

NA Frequency of Detection 115/120 113/119

Average (pCi/L) 0.2 0.2

Thorium-230 T Range (pCi/L) 0.1–0.7 0–0.6

NA Frequency of Detection 7/7 7/7

Average (pCi/L) 0.3 0.2

Source: CDPHE 2007b

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Negative and zero result values were included in the summary statistics.

Radium-226 and thorium-230 “D” and “S” samples were collected between 1995 and 2007. The radium-226 and thorium-230 “T”

samples were only collected in 1995. Lead-210 and polonium-210 were sampled upstream (907) in 2005 (“D” and “S”) and

downstream (904) in 2005 (“D”) and 2006 (“D” and “S”).

133Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment

* The calculated average is higher than the detected concentra tion due to including 1⁄2 the detection limit in the calculation.

CV – comparison value

D – dissolved

MCL – maximum contaminant level

NA – not available

ND – not detected

pCi/L – picocuries per liter

S – suspended

T – total

134Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 47. Sampling data (chemicals ) for local and supermarket foods

Chemical Food Type Average (mg/kg)

Local Supermarket

Barium* Vegetables 4.75 NA

Cadmium* Vegetables 0.215 NA

Chromium* Vegetables 0.095 NA

Manganese* Vegetables 11.25 NA

Molybdenum Chicken 0.19 0.72

Fruits 0.079 0.017

Vegetables 0.667 0.023

Selenium Chicken 0.31 0.18

Fruits 0.024 0.017

Vegetables 0.061 0.020

Strontium* Vegetables 22 NA

Uranium Chicken 0.061 0.001

Fruits 0.0056 0.0013

Vegetables 0.0043 0.0013

Vanadium* Vegetables 0.105 NA

Zinc* Vegetables 7.5 NA

Source: Weston 1996

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Concentrations are reported on a wet weight basis.

Vegetables were also tested for arsenic, beryllium, cobalt, l ead, mercury, nickel, and silver, but none of these chemicals were detected.

*Chicken and fruits were not analyzed for these chemicals.

NA – not available

mg/kg – milligrams per kilogram

135Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 48. Sampling data (radionuclides) for local and supermarket foods

Radionuclide Food Type Average (pCi/kg)

Local Supermarket

Lead-210 Chicken 1.26 1.70

Fruits 1.48 1.18

Vegetables 0.58 0.60

Polonium-210 Chicken 3.79 21.75

Fruits 2.26 1.30

Vegetables 1.13 1.56

Radium-226 Chicken 0.64 2.60

Fruits 1.34 0.05

Vegetables 1.37 0.07

Thorium-228 Chicken 0.39 ND

Fruits 0.33 ND

Vegetables 0.41 1.42

Thorium-230 Chicken 1.01 0.53

Fruits 1.85 ND

Vegetables 0.27 0.29

Uranium-234 Chicken 1.10 1.05

Fruits 1.53 0.34

Vegetables 0.55 0.76

Uranium-235 Chicken ND 0.36

Fruits 0.13 0.13

Vegetables 0.13 0.14

Uranium-238 Chicken 1.59 0.53

Fruits 1.41 0.23

Vegetables 0.44 0.25

Source: Weston 1996

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Concentrations are reported on a wet weight basis.

ND – not detected

pCi/kg – picocuries per kilogram

136Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 49. Sampling data (chemicals) for local pr oduce irrigated with contaminated well water

Chemical Fruits Vegetables

Arsenic Frequency of Detection 2/16 14/43

Average (mg/kg) 0.051 0.077

Maximum (mg/kg) 0.2 0.4

Barium Frequency of Detection 7/16 33/43

Average (mg/kg) 0.44 1.6

Maximum (mg/kg) 0.9 15

Cadmium Frequency of Detection 2/16 18/43

Average (mg/kg) 0.041 0.034

Maximum (mg/kg) 0.23 0.14

Chromium Frequency of Detection 12/16 39/43

Average (mg/kg) 0.052 0.056

Maximum (mg/kg) 0.1 0.19

Cobalt Frequency of Detection 0/16 6/43

Average (mg/kg) ND 0.02

Maximum (mg/kg) ND 0.07

Lead Frequency of Detection 3/16 26/43

Average (mg/kg) 0.13 0.2

Maximum (mg/kg) 1.2 1.9

Manganese Frequency of Detection 16/16 43/43

Average (mg/kg) 0.87 2.4

Maximum (mg/kg) 1.8 11

Molybdenum Frequency of Detection 6/16 41/43

Average (mg/kg) 0.11 0.68

Maximum (mg/kg) 0.3 9.8

Nickel Frequency of Detection 0/16 2/43

Average (mg/kg) ND 0.075

Maximum (mg/kg) ND 0.2

Strontium Frequency of Detection 16/16 43/43

Average (mg/kg) 1.6 4.9

Maximum (mg/kg) 8.5 33

Uranium Frequency of Detection 3/16 14/43

Average (mg/kg) 0.0074 0.0071

Maximum (mg/kg) 0.035 0.041

Vanadium Frequency of Detection 0/16 16/43

Average (mg/kg) ND 0.046

Maximum (mg/kg) ND 0.21

137Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Chemical Fruits Vegetables

Frequency of Detection 16/16 43/43

Zinc Average (mg/kg) 1.4 3.1

Maximum (mg/kg) 4.0 10

Source: Weston 1998

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Concentrations are reported on a wet weight basis.

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.

ND – not detected

mg/kg – milligrams per kilogram

138Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 50. Sampling data (radionuclides) for local produce irrigated with contaminated well water

Radionuclide Fruits Vegetables

Lead-210 Frequency of Detection 3/16 8/43

Average (pCi/kg) 12 21

Maximum (pCi/kg) 21 51

Radium-226 Frequency of Detection 1/16 15/43

Average (pCi/kg) 5.7 6.2

Maximum (pCi/kg) 18 41

Thorium-230 Frequency of Detection 1/16 8/43

Average (pCi/kg) 3.9 5.1

Maximum (pCi/kg) 10 20

Uranium (natural) Frequency of Detection 3/16 14/43

Average (pCi/kg) 5.0 4.8

Maximum (pCi/kg) 23 27

Source: Weston 1998

Averages were calculated using 1⁄2 the reporting detection limit for non-detects.

Concentrations are reported on a wet weight basis.

The dates the samples were collected were not specified in the report. It is assumed to be in the 1994–1996 timeframe.

pCi/kg – picocuries per kilogram



### Table 51. Characteristics of Cotter M ill’s Ambient Air Monitoring Stations

Monitor

Code Monitor Location Years of

Operation Monitor

Type Area Description

AS-202 East Boundary 1979 – present Perimeter Eastern perimeter of Cotter Mill facility

AS-203 South Boundary 1979 – present Perimeter Southern perimeter of Cotter Mill facility

AS-204 West Boundary 1979 – present Perimete r Western perimeter of Cotter Mill facility

AS-206 North Boundary 1981 – present Perimeter Northern perimeter of Cotter Mill facility

AS-209 Mill entrance road 1994 – present Perimeter Entrance road to Cotter Mill

AS-210 Shadow Hills Estates 1997 – present Off-site Near Shadow Hills Golf Club

AS-212 Nearest resident 1999 – present Off-site Residential

LP-1/LP-2 Lincoln Park 1980 – present Off-site Residential

CC-1/CC-2 Cañon City 1979 – present Off-site Residential

OV-3 Oro Verde 1981 – present Off-site Remote (1 mile west of AS-204)

Notes: Both the Lincoln Park and Cañon City monitoring stations moved locations in the 1991-1992 time frame. The

original station in Lincoln Park (LP-1) operated from 1980 to 1992, and the new station (LP-2) operated from 1991

to the present. The original station in Cañon City (CC-1) operated from 1979 to 1992, and the new station (CC-2)

operated from 1991 to the present.

139Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 52. Average Annual nat 

### U Concentrations 1979-2008 ( μ Ci/ml)

Year Perimeter Monitoring Stations Off-Site Monitoring Stations

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 CC-1/2 OV-3

1979 6.19E-15 1.50E-15 2.26E-15

-­ -­ -­ -­ -­ 1.00E-15

-­



### 1980 3.71E-15 1.55E-15 2.82E-15

-­ -­ -­ -­ 8.36E-16 1.40E-15

-­



### 1981 4.07E-15 1.54E-15 5.28E-15 8.30E-15

-­ -­ -­ 1.03E-15 1.02E-15 1.37E-15



### 1982 2.31E-15 1.26E-15 2.48E-14 2.79E-15

-­ -­ -­ 5.28E-16 4.79E-16 5.96E-16



### 1983 1.26E-15 1.43E-15 1.32E-15 1.63E-15

-­ -­ -­ 4.77E-16 6.86E-16 5.03E-16



### 1984 5.50E-16 7.64E-16 8.36E-16 1.52E-15

-­ -­ -­ 2.78E-16 3.27E-16 4.01E-16



### 1985 1.42E-15 1.22E-15 8.96E-16 1.92E-15

-­ -­ -­ 4.56E-16 5.77E-16 6.66E-16



### 1986 6.71E-16 6.56E-16 4.05E-16 9.36E-16

-­ -­ -­ 2.95E-16 2.93E-16 4.84E-16



### 1987 8.08E-16 1.03E-15 1.09E-15 1.05E-15

-­ -­ -­ 4.66E-16 5.12E-16 4.60E-16



### 1988 6.73E-16 6.96E-16 9.03E-16 5.51E-16

-­ -­ -­ 1.85E-16 1.95E-16 1.89E-16



### 1989 9.58E-17 9.95E-17 2.86E-16 3.62E-17

-­ -­ -­ 8.37E-17 9.38E-17 6.38E-17



### 1990 5.59E-17 3.14E-17 1.06E-16 3.10E-17

-­ -­ -­ 6.18E-17 1.26E-16 9.09E-17



### 1991 1.12E-16 9.18E-17 2.65E-16 1.24E-16

-­ -­ -­ 1.70E-16 1.73E-16 2.60E-16



### 1992 6.55E-17 7.84E-17 1.12E-16 6.48E-17

-­ -­ -­ 9.71E-17 9.40E-17 8.23E-17



### 1993 7.13E-17 9.08E-17 1.61E-16 6.30E- 17

-­ -­ -­ 8.26E-17 1.20E-16 2.55E-16



### 1994 1.25E-16 4.68E-17 1.00E-16 3.68E-17 1.55E-16

-­ -­ 9.68E-17 8.12E-17 2.54E-16



### 1995 2.99E-16 5.86E-17 1.53E-16 5.23E-17 2.11E-16

-­ -­ 9.34E-17 1.26E-16 4.83E-16



### 1996 2.25E-16 1.43E-16 2.26E-16 8.62E-17 2.44E-16 7.89E-17

-­ 9.73E-17 1.25E-16 5.93E-17



### 1997 1.23E-16 1.18E-16 2.20E-16 1.19E-16 1.51E-16 1.75E- 16

-­ 1.27E-16 2.00E-16 9.48E-17



### 1998 1.32E-16 1.02E-16 3.29E-16 1.06E-16 2.27E-15 2.32E-16

-­ 8.13E-17 7.50E-17 2.43E-16



### 1999 4.06E-16 1.49E-16 2.91E-16 3.23E-16 1.46E-15 2.82E-16 4.59E-16 1.16E-16 9.41E-17 7.97E-17



### 2000 4.33E-16 2.04E-16 2.61E-16 1.63E-16 1.49E-15 1.89E-16 4.82E-16 5.39E-17 5.33E-17 5.39E-17



### 2001 4.96E-16 6.19E-16 4.96E-16 5.29E-16 1.32E-15 2.06E-16 2.88E-16 4.96E-17 3.80E-17 5.18E-17



### 2002 6.50E-16 4.93E-16 6.21E-16 3.24E-16 9.91E-16 3.69E-16 4.05E-16 2.46E-16 1.59E-16 2.05E-16



### 2003 3.55E-16 2.19E-16 2.55E-16 2.01E-16 4.91E-16 2.21E-16 2.20E-16 2.11E-16 2.07E-16 2.62E-16



### 2004 2.51E-16 1.95E-16 2.40E-16 1.99E-16 6.27E-16 1.40E-16 2.30E-16 9.69E-17 9.68E-17 8.61E-17



### 2005 4.54E-16 2.77E-16 2.87E-16 1.58E-16 3.97E-15 4.85E-16 5.25E-16 1.68E-16 1.29E-16 1.23E-16



### 2006 5.14E-16 2.68E-16 3.24E-16 2.12E-16 1.72E-15 6.62E-16 3.40E-16 2.20E-16 1.75E-16 1.87E-16



### 2007 3.56E-16 1.51E-16 2.03E-16 1.39E-16 3.13E-16 1.46E-16 1.33E-16 1.41E-16 1.43E-16 1.27E-16



### 2008 4.36E-16 8.61E-17 1.72E-16 8.44E-17 2.17E-16 9.77E-17 9.78E-17 9.02E-17 8.97E-17 6.43E-17

Notes: For station LP-1/2, data from 1980-199 2 were collected at LP-1, and data fr om 1993-2008 were collected at LP-2.

For station CC-1/2, data from 1979-1992 were collected at CC-1, and data from 1993-2008 were collected

at CC-2.

Shaded cells are the highest annual averages for the calendar year; “

-- ” indicates that no data are available because

the station was not yet operating.

140Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 53. Average Annual 230 

### Th Concentrations 1979-2008 ( μ Ci/ml)

Year Perimeter Monitoring Stations Off-Site Monitoring Stations

AS-202 AS-203 AS-204 AS-206 AS-209 AS-210 AS-212 LP-1/2 CC-1/2 OV-3

1979 2.33E-15 1.05E-15 8.08E-15

-­ -­ -­ -­ -­ 3.07E-16

-­



### 1980 2.50E-16 8.76E-16 2.81E-16

-­ -­ -­ -­ 8.17E-17 1.30E-16

-­



### 1981 2.60E-15 3.50E-15 3.00E-14

8.95E-14 6.93E-15

-­ -­ -­ 1.42E-16 8.17E-17 3.92E-16



### 1982 2.12E-14 1.94E-14 1.26E-14

-­ -­ -­ 7.49E-16 9.18E-16 3.15E-15



### 1983 5.86E-15 9.79E-15 5.64E-15 8.26E-15

-­ -­ -­ 3.74E-16 3.12E-16 1.07E-15



### 1984 1.64E-15 2.98E-15 3.82E-15 6.35E-15

-­ -­ -­ 2.69E-16 2.00E-16 2.89E-16



### 1985 1.84E-15 2.15E-15 4.86E-15 3.73E-15

-­ -­ -­ 2.60E-16 2.64E-16 2.84E-16



### 1986 3.70E-15 5.55E-15 3.13E-15 4.68E-15

-­ -­ -­ 3.70E-16 3.08E-16 2.41E-16



### 1987 1.21E-15 1.29E-15 2.28E-15

5.85E-15

9.17E-16 1.08E-15

-­ -­ -­ 2.06E-16 1.77E-16 9.90E-17



### 1988 2.58E-15 3.51E-15 2.05E-15

-­ -­ -­ 1.41E-16 1.72E-16 1.70E-16



### 1989 6.33E-16 3.85E-16 1.08E-16

-­ -­ -­ 8.93E-17 9.03E-17 9.24E-17



### 1990 7.63E-16 4.00E-16 5.86E-16 1.09E-16

-­ -­ -­ 7.40E-17 7.04E-17 7.20E-17



### 1991 7.25E-16 4.59E-16 8.75E-16

4.71E-16

6.42E-16 2.83E-16

-­ -­ -­ 1.91E-16 1.25E-16 1.33E-16



### 1992 4.57E-16 2.20E-16 9.46E-17

-­ -­ -­ 6.58E-17 5.98E-17 9.56E-17



### 1993 4.45E-16 3.03E-16 9.32E-17

-­ -­ -­ 1.06E-16 9.17E-17 2.33E-16



### 1994 1.18E-15

1.65E-15

2.21E-15 2.96E-16 1.08E-15 1.24E-16 9.20E -16

-­ -­ 1.54E-16 1.16E-16 2.83E-16



### 1995 5.33E-16 1.24E-15 1.18E-16 8.88E -16

-­ -­ 9.80E-17 1.12E-16 3.30E-16



### 1996 2.95E-16 8.13E-16 8.85E-17 7.67E- 16 2.33E-16

-­ 7.11E-17 5.08E-17 6.39E-17



### 1997 7.64E-16 1.31E-16 6.17E-16 6.49E-17 1.99E-15 3.82E-16

-­ 8.37E-17 7.86E-17 3.24E-17



### 1998 2.88E-15

3.76E-15 2.02E-16 9.34E-16 1.15E-16 2.17E- 15 3.32E-16

-­ 7.70E-17 7.99E-17 7.82E-17



### 1999 3.24E-16 1.09E-15 1.84E-16 2.19E-15 4.15E-16 3.02E-16 7.37E-17 9.51E-17 1.11E-16



### 2000 1.22E-15 2.48E-16 1.01E-15 2.02E-16 4.16E-15

4.15E-15

1.25E-15

1.40E-15

6.57E-16

3.41E-15

1.40E-15

1.05E-15 4.71E-16 6.69E-16 1.47E-16 1.57E-16 1.27E-16



### 2001 8.20E-16 5.19E-16 9.67E-16 2.61E-16 4.04E-16 4.61E-16 1.56E-16 9.95E-17 1.13E-16



### 2002 5.84E-16 2.76E-16 5.95E-16 2.57E-16 2.38E-16 3.13E-16 8.15E-17 8.54E-17 8.55E-17



### 2003 5.19E-16 2.62E-16 4.90E-16 9.73E-17 4.11E-16 1.77E-16 8.27E-17 8.91E-17 5.30E-17



### 2004 2.17E-16 8.26E-17 3.87E-16 8.33E-17 2.26E-16 1.08E-16 5.36E-17 5.62E-17 6.07E-17



### 2005 3.17E-16 1.97E-16 3.51E-16 2.64E-16 4.85E-16 4.81E-16 1.04E-16 1.05E-16 1.08E-16



### 2006 5.17E-16 2.91E-16 4.74E-16 1.77E-16 4.73E-16 3.27E-16 2.73E-16 2.04E-16 2.85E-16



### 2007 6.62E-16 1.90E-16 4.32E-16 1.48E-16 2.77E-16 2.23E-16 1.68E-16 1.57E-16 1.53E-16



### 2008 7.21E-16 1.87E-16 5.12E-16 1.32E-16 6.21E-16 2.88E-16 2.05E-16 1.11E-16 1.08E-16 1.16E-16

Notes: For station LP-1/2, data from 1980-199 2 were collected at LP-1, and data fr om 1993-2008 were collected at LP-2.

For station CC-1/2, data from 1979-1992 were collected at CC-1, and data from 1993-2008 were collected

at CC-2.

Shaded cells are the highest annual averages for the calendar year; “

-- ” indicates that no data are available because

the station was not yet operating; bold cells are concentrations above Cotter Mill’s regulatory limit

141Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 54. Average Annual232Th Concentrations 2001-2008 (μCi/ml)YearPerimeter Monitoring StationsOff-Site Monitoring StationsAS-202AS-203AS-204AS-206AS-209AS-210AS-212LP #2CC #2OV-320015.78E-177.62E-176.97E-176.37E-178.32E-174.58E-176.67E-176.85E-178.33E-175.68E-1720024.67E-173.81E-173.09E-174.55E-174.34E-173.17E-173.35E-175.36E-173.51E-174.68E-1720034.57E-174.14E-174.84E-172.06E-175.72E-174.61E-173.71E-176.21E-174.61E-173.96E-1720041.39E-172.53E-172.53E-171.40E-171.57E-171.99E-171.65E-173.24E-172.28E-172.39E-1720052.83E-172.40E-172.86E-173.09E-173.36E-172.53E-173.42E-173.99E-173.57E-173.45E-1720064.11E-175.18E-174.82E-174.29E-175.54E-174.33E-174.79E-176.25E-174.98E-173.65E-1720074.07E-173.47E-174.60E-174.14E-174.12E-173.99E-173.51E-175.43E-174.48E-173.92E-1720081.08E-171.63E-171.15E-179.89E-181.57E-172.30E-171.26E-173.13E-172.25E-172.03E-17Note:Shaded cells are the highest annualaverages for the calendar year; “--” indicates that no data are availablebecause the station was not yet operating142Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 55. Average Annual226Ra Concentrations 1979-2008 (μCi/ml)YearPerimeter Monitoring StationsOff-Site Monitoring StationsAS-202AS-203AS-204AS-206AS-209AS-210AS-212LP-1/2CC-1/2OV-319791.55E-153.75E-167.89E-15-­-­-­-­-­3.07E-16-­19803.61E-154.19E-157.81E-161.62E-15-­-­-­-­2.78E-161.58E-15-­19812.35E-152.94E-152.96E-15-­-­-­3.79E-164.59E-166.30E-1619826.53E-156.92E-155.08E-153.81E-153.82E-15-­-­-­6.07E-164.02E-161.25E-1519832.00E-154.95E-152.85E-15-­-­-­9.42E-171.76E-165.30E-1619841.11E-151.84E-153.63E-152.20E-15-­-­-­1.18E-161.67E-161.87E-1619859.63E-151.11E-151.78E-151.97E-15-­-­-­1.69E-161.88E-161.89E-1619861.47E-151.98E-151.61E-152.60E-15-­-­-­1.43E-163.45E-162.22E-1619875.91E-167.52E-161.19E-152.53E-153.30E-161.92E-162.68E-161.50E-152.49E-164.74E-16-­-­-­1.83E-161.15E-161.89E-1619881.29E-152.05E-153.60E-16-­-­-­1.24E-165.09E-171.09E-1619892.72E-161.81E-164.79E-17-­-­-­1.02E-168.89E-177.77E-1719901.75E-161.68E-164.36E-17-­-­-­6.69E-178.36E-177.82E-1719911.19E-161.25E-166.17E-17-­-­-­6.85E-177.16E-171.37E-1619928.46E-177.30E-173.71E-17-­-­-­5.10E-175.80E-171.17E-1619939.11E-171.14E-165.99E-17-­-­-­6.14E-176.72E-172.20E-1619941.03E-167.57E-171.69E-164.96E-171.55E-16-­-­7.80E-178.68E-172.64E-163.99E-1619951.21E-161.14E-162.07E-167.46E-172.06E-16-­-­6.88E-171.05E-1619961.78E-161.02E-162.08E-165.33E-172.11E-165.82E-17-­5.22E-176.67E-173.59E-1719971.29E-167.55E-172.01E-165.66E-179.45E-161.06E-16-­5.09E-175.40E-174.84E-1719982.89E-168.22E-172.95E-169.43E-171.34E-151.21E-16-­6.21E-176.71E-174.24E-1719994.18E-161.29E-163.81E-161.02E-161.26E-151.46E-162.13E-168.27E-179.21E-175.90E-1720003.37E-161.53E-164.64E-161.40E-162.38E-152.21E-164.60E-167.41E-174.64E-175.10E-1720012.15E-162.09E-164.36E-161.38E-161.92E-151.51E-161.99E-167.01E-176.82E-175.16E-1720021.55E-161.17E-162.34E-167.51E-173.83E-161.05E-161.14E-168.41E-176.07E-176.72E-1720031.45E-161.10E-161.75E-168.02E-172.96E-161.23E-169.65E-179.70E-178.40E-178.93E-1720047.81E-177.35E-171.41E-166.14E-173.30E-169.05E-178.14E-175.79E-176.26E-174.95E-1720051.78E-161.56E-161.75E-161.97E-162.29E-152.49E-162.95E-161.08E-161.22E-169.58E-1720064.10E-161.40E-162.17E-161.34E-167.52E-161.69E-161.42E-161.20E-161.03E-161.15E-1620078.67E-161.11E-162.07E-161.00E-162.31E-161.16E-169.11E-171.09E-169.66E-171.11E-1620087.92E-167.36E-172.00E-165.16E-171.78E-167.33E-175.71E-176.21E-175.91E-173.28E-17Notes:For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. For station CC-1/2, data from 1979-1992 werecollected at CC-1, and data from 1993-2008 werecollected at CC-2. Shaded cells are the highest annual averages for the calendar year; “--” indicates that nodata are available because the station was not yet operating.143Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 56. Average Annual210Pb Concentrations 1979-2008 (μCi/ml)YearPerimeter Monitoring StationsOff-Site Monitoring StationsAS-202AS-203AS-204AS-206AS-209AS-210AS-212LP-1/2CC-1/2OV-319792.11E-141.65E-142.08E-14-­-­-­-­-­2.30E-14-­19801.81E-141.69E-141.25E-14-­-­-­-­1.86E-141.98E-14-­19812.01E-141.72E-144.71E-142.34E-14-­-­-­1.57E-141.70E-142.11E-1419823.87E-144.35E-149.95E-144.07E-14-­-­-­2.50E-143.31E-144.05E-1419831.70E-141.73E-141.82E-141.95E-14-­-­-­1.29E-141.79E-141.44E-1419841.44E-141.46E-141.60E-141.43E-14-­-­-­1.26E-141.15E-141.48E-1419859.12E-158.12E-158.80E-159.30E-15-­-­-­9.97E-151.14E-149.90E-1519861.26E-141.19E-141.12E-141.22E-14-­-­-­1.07E-141.22E-148.81E-1519871.95E-141.92E-142.22E-142.35E-14-­-­-­2.17E-142.01E-141.43E-1419882.15E-141.94E-142.10E-141.93E-14-­-­-­2.04E-142.11E-141.76E-1419892.28E-142.30E-141.98E-142.34E-14-­-­-­2.43E-142.35E-142.40E-1419902.05E-142.10E-142.07E-142.07E-14-­-­-­2.24E-142.00E-141.95E-1419912.40E-142.15E-142.15E-142.13E-14-­-­-­2.23E-142.15E-141.07E-1419922.16E-142.00E-142.20E-142.19E-14-­-­-­1.99E-141.61E-142.20E-1419932.38E-142.35E-142.35E-142.49E-14-­-­-­2.22E-142.13E-142.10E-1419942.21E-142.07E-142.10E-142.24E-142.18E-14-­-­2.33E-142.38E-142.06E-1419952.07E-142.07E-142.02E-142.01E-142.11E-14-­-­1.97E-142.03E-141.74E-1419962.02E-142.01E-142.16E-142.21E-142.11E-14-­-­2.08E-141.96E-141.98E-1419972.21E-142.07E-142.12E-142.20E-142.26E-142.05E-14-­2.13E-142.00E-141.98E-1419982.01E-142.07E-141.98E-142.11E-142.01E-141.93E-14-­2.01E-142.01E-141.93E-1419992.14E-141.94E-141.83E-141.84E-142.03E-141.94E-142.03E-142.03E-141.94E-141.78E-1420002.07E-142.05E-142.01E-142.23E-142.37E-142.00E-142.07E-142.16E-142.08E-142.03E-1420013.10E-143.04E-142.91E-143.11E-143.06E-142.94E-143.12E-143.06E-142.96E-142.79E-1420022.36E-142.20E-142.28E-142.25E-142.30E-142.37E-142.40E-142.46E-142.33E-142.17E-1420032.19E-142.11E-142.16E-142.06E-142.28E-142.12E-142.18E-142.11E-141.94E-142.27E-1420041.72E-141.64E-141.58E-141.60E-141.66E-141.45E-141.79E-141.56E-141.54E-141.59E-1420052.45E-142.74E-142.82E-142.54E-143.11E-142.91E-142.92E-143.11E-143.15E-142.94E-1420062.11E-142.31E-142.47E-142.31E-142.09E-142.08E-141.89E-141.98E-141.89E-142.12E-1420071.88E-141.64E-141.79E-141.82E-141.54E-141.58E-141.49E-141.66E-141.61E-141.72E-1420081.65E-141.48E-141.64E-141.93E-141.66E-141.73E-141.57E-141.67E-141.61E-141.61E-14Notes:For station LP-1/2, data from 1980-1992 were collected at LP-1, and data from 1993-2008 were collected at LP-2. For station CC-1/2, data from 1979­1992 were collected at CC-1, and datafrom 1993-2008 werecollected at CC-2.Shaded cells are the highest annualaverages for the calendar year; “--” indicates that no data are availablebecause the station was not yet operating.144Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 57.220Rn/222Rn Concentrations 2002-2008 (pCi/m3)YearPerimeter Monitoring StationsOff-Site Monitoring StationsAS-202AS-203AS-204AS-206AS-209AS-210AS-212CC-1LP-1OV-32002543975112569314757006988756736252003700825775900625675700375800567200415008501025950110085092582587582520059251025850700102567577570090080020061250127512751450140011251275107513751200200710001100117511001250975825925117597520088509009259501075950850800925825Notes:Data are presented for only those years when measurements quantified combined levels of the two isotopes.Shaded cells are the highest annualaverages for the calendar year.145Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable 58. Environmental TLD Measurements, 1979-2008 (μR/hr)YearPerimeter Monitoring StationsOff-Site Monitoring StationsAS-202AS-203AS-204AS-206AS-209AS-210AS-212CC-1LP-1OV-3197914.012.612.7-­-­-­-­11.811.4-­198013.411.712.9-­-­-­-­10.411.4-­198114.312.812.7-­-­-­-­10.612.312.3198213.712.614.720.4-­-­-­9.911.212.7198313.612.614.215.6-­-­-­10.611.612.0198414.514.314.614.8-­-­-­12.311.213.2198514.313.514.514.8-­-­-­10.511.212.3198613.913.714.514.2-­-­-­11.010.711.8198712.912.512.612.6-­-­-­9.69.710.4198815.013.612.813.4-­-­-­9.311.610.2198914.714.915.315.9-­-­-­10.613.711.9199013.213.114.815.2-­-­-­9.611.511.7199114.113.215.717.5-­-­-­10.012.912.4199213.713.216.018.3-­-­-­9.612.111.3199312.512.614.415.6-­-­-­8.610.710.9199414.313.815.916.227.8-­-­10.812.112.3199512.513.714.015.423.0-­-­9.210.311.3199613.113.214.516.227.213.0-­9.710.911.4199712.613.113.815.729.112.3-­9.110.211.1199812.312.013.415.928.012.0-­9.010.311.5199912.712.013.816.029.612.29.19.310.610.9200012.712.614.716.627.712.59.39.510.711.4200113.714.315.418.626.213.99.710.412.012.2200214.014.415.917.730.314.310.510.512.312.6200312.813.314.815.527.713.310.010.011.711.8200413.614.115.514.725.514.210.910.512.212.5200512.813.514.813.822.912.99.910.111.511.5200612.713.414.614.221.512.69.510.111.511.7200712.913.214.614.117.812.79.510.111.511.6200813.913.515.514.918.713.310.210.812.212.6Notes:Shaded cells are the highest annualaverages for the calendar year; “--” indicates that no data are available because the station was not yet operating.146Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table 59. TSP Air Concentrations (μg/m 3 

### ) from 1969-1987

Year Cañon City Lincoln Park

Maximum Average Maximum Average

1969 172 64.2

-­ -­



### 1970 200 55.9

-­ -­



### 1971 148 58.7

-­ -­



### 1972 240 69.9

-­ -­



### 1973 229 66.1

-­ -­



### 1974 187 58

-­ -­



### 1975 419 73.7

-­ -­



### 1976 174 56.8

-­ -­



### 1977 227 62.7

-­ -­



### 1978 313 84.7

-­ -­



### 1979 286 72.6

-­ -­



### 1980 304 70.4

-­ -­



### 1981 180 56.8 61* 8.2*



### 1982 525 84 228 51.7



### 1983 187 65.2 106 77.6



### 1984 571 70.9

-­ -­



### 1985 334 64.8

-­ -­



### 1986 402 66.3

-­ -­



### 1987 385 65.2

-­ -­

Notes: Data downloaded from EPA’s Air Quality System database.

EPA’s former annual average National Ambient Air Quality Standard for TSP was 75 μg/m 3

. * The TSP monitoring station in Lincoln Park started operating late in 1981; therefore, the statistics reported are not

representative of the entire calendar year.



### Table 60. Monitoring Data for Constituents in TSP (1978-1987)

Constituent Location Years of Data Concentrations (μg/m 3 

### )

Highest 24-Hour

Average Highest Annual

Average

Iron Lincoln Park 1981-1982 1.2 0.8

Lead Lincoln Park 1981-1982 0.1 0.034

Manganese Lincoln Park 1981-1982 0.03 0.0185

Nitrate Cañon City 1978-1987 14.3 2.35

Lincoln Park 1981-1982 4.7 1.81

Sulfate Cañon City 1978-1987 18.4 5.99

Lincoln Park 1981-1982 13 6.48

Zinc Lincoln Park 1981-1982 0.04 0.0283

Notes Data downloaded from EPA’s Air Quality System database.

147Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



# Appendix B - Site Figures

149Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 1. Location of the Cotter Mill, Lincoln Park, and Cañon City

Source: Galant et al. 2007

150Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 2. Demographics within 1 mile of the Cotter Mill property

151Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 3. Wind Rose for Cotter Mill, 2008

152Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 4. Molybdenum Plume Map

Source: Cotter 2008

153Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 5. Uranium Plume Map

Source: Cotter 2008

154Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 6. Wells in Lincoln Park used for personal consumption

Source: CDPHE 2007b (coordinates)

155Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 7. Molybdenum concentrations inwells used for personal consumptionMolybdenum in Personal Consumption Wells0.000.050.100.150.200.250.30 Mar-84 Mar-85 Mar-86 Mar-87 Mar-88 Mar-89 Mar-90 Mar-91 Mar-92 Mar-93 Mar-94 Mar-95 Mar-96 Mar-97 Mar-98 Mar-99 Mar-00 Mar-01 Mar-02 Mar-03 Mar-04 Mar-05 Mar-06 Mar-07Date Sampled

Molybdenum Concentration (mg/L )Well 165Well 168Well 189Well 198Well 219Well 255State StandardSource: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.156Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 8. Dissolved uranium concentrationsin wells used for personal consumptionDissolved Uranium in Personal Consumption Wells0.000.010.020.030.040.050.060.070.08 Mar-84 Mar-85 Mar-86 Mar-87 Mar-88 Mar-89 Mar-90 Mar-91 Mar-92 Mar-93 Mar-94 Mar-95 Mar-96 Mar-97 Mar-98 Mar-99 Mar-00 Mar-01 Mar-02 Mar-03 Mar-04 Mar-05 Mar-06 Mar-07Date Sampled

Dissolved Uranium Concentration (mg/L )Well 165Well 168Well 189Well 198Well 219Well 255MCLSource: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.157Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 9. Wells in Lincoln Park used to irrigate fruit and vegetable gardens

Source: CDPHE 2007b (coordinates)

158Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 10. Wells in Lincoln Park used to water livestock

Source: CDPHE 2007b (coordinates)

159Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 11. Wells in Lincoln Park used to water lawns

Source: CDPHE 2007b (coordinates)

160Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 12. Molybdenum concentrations in Well 138Molybdenum in Well 1380102030405060 Jun-68 Jun-69 Jun-70 Jun-71 Jun-72 Jun-73 Jun-74 Jun-75 Jun-76 Jun-77 Jun-78 Jun-79 Jun-80 Jun-81 Jun-82 Jun-83 Jun-84 Jun-85 Jun-86 Jun-87 Jun-88 Jun-89 Jun-90 Jun-91 Jun-92 Jun-93 Jun-94 Jun-95 Jun-96 Jun-97 Jun-98 Jun-99 Jun-00Date Sampled

Molybdenum Concentration (mg/L )Source: CDPHE 2007b161Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 13. Selenium concentrations in Well 138Selenium in Well 1380.000.020.040.060.080.100.120.14 Jan-74 Jan-75 Jan-76 Jan-77 Jan-78 Jan-79 Jan-80 Jan-81 Jan-82 Jan-83 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00Date Sampled

Selenium Concentration (mg/L)Source: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.162Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 14. Dissolved uranium concentrations in Well 138Dissolved Uranium in Well 1380123456 Jun-68 Jun-69 Jun-70 Jun-71 Jun-72 Jun-73 Jun-74 Jun-75 Jun-76 Jun-77 Jun-78 Jun-79 Jun-80 Jun-81 Jun-82 Jun-83 Jun-84 Jun-85 Jun-86 Jun-87 Jun-88 Jun-89 Jun-90 Jun-91 Jun-92 Jun-93 Jun-94 Jun-95 Jun-96 Jun-97 Jun-98 Jun-99 Jun-00Date Sampled

Dissolved Uranium Concentration (mg/L)Source: CDPHE 2007b16350

Molybdenum Concentration (mg/L )403020100-10Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 15. Molybdenum concentrations in all groundwater wells evaluatedMolybdenum60 May-68 May-70 May-72 May-74 May-76 May-78 May-80 May-82 May-84 May-86 May-88 May-90 May-92 May-94 May-96 May-98 May-00 May-02 May-04 May-06Date SampledSource: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.164Selenium Concentration (mg/L)0.100.080.060.040.020.00Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 16. Selenium concentrationsin all groundwater wells evaluatedSelenium0.140.12 Jan-74 Jan-75 Jan-76 Jan-77 Jan-78 Jan-79 Jan-80 Jan-81 Jan-82 Jan-83 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00Date SampledSource: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.16556

Dissolved Uranium Concentration (mg/L)43210-1Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentFigure 17. Dissolved uranium concentrations in all groundwater wells evaluatedDissolved Uranium

Apr-62 Apr-64 Apr-66 Apr-68 Apr-70 Apr-72 Apr-74 Apr-76 Apr-78 Apr-80 Apr-82 Apr-84 Apr-86 Apr-88 Apr-90 Apr-92 Apr-94 Apr-96 Apr-98 Apr-00 Apr-02 Apr-04 Apr-06Date SampledSource: CDPHE 2007bNon-detected concentrations were plotted as 1⁄2 the reporting detection limit.166Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 18. Sampling zones established during the

1998 Supplemental Human Heal th Risk Assessment

Source: Weston 1998

167Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 19. Locations of soil samples taken alon g the county road and Cotter Mill’s access road

Source: MFG 2005

168Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 20. Locations of soil sampl es taken by CDPHE in January 2003

Source: CDPHE 2007b (coordinates)

169Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 21. Location of air sampling lo cations where soil samp les are collected

Source: Cotter 2007

Note: An additional air sampling station is located in Cañon City (not depicted on the figure).

170Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 22. Sand Creek Cleanup Project

Source: Cotter 2000

171Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Figure 23. Approximate Locations of Cotter Mill Monitoring Stations

Notes: Figure reproduced from: Cotter 2008

172Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



# APPENDIX C:

ATSDR’s Evaluation Process

And

Exposure Dose Calculations

173Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### ATSDR’s Evaluation Process

Step 1 – Comparison Values and the Screening Process

To evaluate the available data, ATSDR used comparison values (CVs) to determine which

chemicals to examine more clos ely. CVs are the contaminant con centrations found in a specific

media (for example: air, soil, or water) and are us ed to select contaminants for further evaluation.

CVs incorporate assumptions of daily exposure to the chemical and a standard amount of air,

water, or soil that someone may inhale or ingest each day. CVs are generated to be conservative

and non-site specific. These values are used only to screen out ch emicals that do not need further

evaluation; CVs are not intended as environmental clean-up levels or to indicate that health

effects occur at concentrations that exceed these values.

CVs can be based on either carcinogenic (cance r-causing) or non-carcinoge nic effects. Cancerbased comparison values are calculated from th e U.S. Environmental Protection Agency’s (EPA)

oral cancer slope factor (CSF) or inhalation risk unit. CVs based on cancerous effects account for

a lifetime exposure (70 years) with an unacceptabl e theoretical excess lifetime cancer risk of 1

new case per 1 million exposed people. Non-can cer values are calculated from ATSDR’s

Minimal Risk Levels (MRLs), EPA’s Refe rence Doses (RfDs), or EPA’s Reference

Concentrations (RfCs). When a cancer and non- cancer CV exists for the same chemical, the

lower of these values is used in the comparison for conservatism.

Step 2 – Evaluation of Public Health Implications

The next step in the evaluation process is to take those contaminants that are above their

respective CVs and further identify which chemicals and exposure situations are likely to be a

health hazard. Separate child and adult exposure dos es (or the amount of a contaminant that gets

into a person’s body) are calculated for site-s pecific exposure scenarios, using assumptions

regarding an individual’s likelihood of accessing th e site and contacting contamination. A brief

explanation of the calculation of estimated exposur e doses is presented below. Calculated doses

are reported in units of milligrams per kilograms per day (mg/kg/day). Separate calculations have

been performed to account for non-cancer and can cer health effects, if applicable, for each

chemical based on the health impacts reported for each chemical. Some chemicals are associated

with non-cancer effects while th e scientific literature many indi cate that cancer-related health

impacts are not expected from exposure.

174Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Exposure Dose Factors and Calculations

When chemical concentrations at the site exceed the established CVs, it is necessary for a more

thorough evaluation of the chemical to be conducte d. In order to evaluate the potential for human

exposure to contaminants present at the site a nd potential health eff ects from site-specific

activities, ATSDR estimates human exposure to the site contaminant from different

environmental media by calculating exposure doses.

A discussion of the calculations and assumptions us ed in this assessment is presented below. The

equations are based on the EPA Risk Assessm ent Guidance for Superfund, Part A (1989), or

ATSDR’s Public Health Guidan ce Manual (2005), unless otherwis e specified. Assumptions used

were based on default values, EPA’s Exposur e Assessment Handbook (1997) or Child-Specific

Exposure Factors Handbook (2008), or professional (site-specific) judgment. When available,

site-specific information is used to estimate exposures.

Ingestion of Chemicals in Well Water:

The exposure dose formula used for the ingestion of chemicals in well water is:



### Exposure Dose (ED) = C x IR x EF x ED

BW x AT

Where:

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)

C

= concentration of contaminant in wa ter in milligrams per liter (mg/L)

IR = ingestion rate in liters per day (L/day)

EF = exposure frequency (days/year)

ED = exposure duration (years)

BW = body weight (kg)

AT = averaging time, days (equal to ED fo r non-carcinogens and 70 year lifetime for

carcinogens, i.e., 70 years x 365 days/year)

Note: In the intake equation, averaging tim e (AT) for exposure to non-carcinogenic compounds

is always equal to ED; whereas, for carcinogens a 70 year AT is still used in order to compare to

EPA’s cancer slope factors typi cally based on that value.

This pathway assumes that an adult resident drin ks 2 liters (L) of water per day for 350 days per

year. In terms of exposure durati on (ED), the adult resident is a ssumed to live in the same home

and drink the same well water for 30 years. The drinking water ingestion rate for children was

assumed to be 1 L per day for 350 days per year for 6 years. For average body weight, 70 kg and

16 kg were used for adults and children, respectively.

ATSDR used the average chemical concentra tion in Well 186 to represent a high exposure

scenario from a single well. Well 186 was selected because it consistently contained the highest

chemical concentrations over time. The average c oncentration for all private wells was used to

represent exposures to a typical well user.

175Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable C1. Summary of Exposure Factors andExposure Doses for the Drinking Water Pathway for Chemicals at the Cotter Mill SiteChemicalChemicalConcentration(mg/L)DailyIngestionRate(L/day)ExposureFrequency(days/yr)ExposureDuration(yrs)BodyWeight(kg)AveragingTime(days)Exposure Dose(mg/kg/day)HealthGuideline(mg/kg/day)Drinking Water Pathway: Ingestion – ADULT and CHILDMolybdenumADULT0.16WELL 189*HIGH EXPOSURE23503070109500.0040.005 ChronicOral RfDMolybdenumCHILD135061621900.010MolybdenumADULT0.082All wellsTYPICALEXPOSURE23503070109500.002MolybdenumCHILD135061621900.005UraniumADULT0.048Well 189*HIGH EXPOSURE23503070109500.0010.002IntermediateOral MRLUraniumCHILD135061621900.003UraniumADULT0.028All wellsTYPICALEXPOSURE23503070109500.0008UraniumCHILD135061621900.002Boldedtype exceeds a comparison value.*“Well 189” represents a high exposure scenario. This wellcontained the highest level of chemicals in the sampled group.“All wells” is used to represent an average exposurescenario for the average private well drinker.176Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Accidental Ingestion of Chemicals in Soil

The exposure dose formula for inci dental ingestion of chemical s soil and/or sediment is:

Exposure Dose (ED) = C × IR× EF × ED × CF

BW ×

AT

Where:

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)

C = concentration of contaminant in soil in milligrams per kilogram (mg/kg or ppm)

IR = ingestion rate in milligrams per day (mg/day)

EF = exposure frequency (days/year)

ED = exposure duration (years)

CF = conversion factor (10 -6 

### kg/mg)

BW = body weight (kg)

AT = averaging time, days (equal to ED fo r non-carcinogens and 70 year lifetime for

carcinogens, i.e., 70 years x 365 days/year)

This pathway assumes that the average adolescen t (11 to 16 years of age) or adult resident

accidentally ingests 100 milligrams of soil per da y. Because the area is in a primarily vacant

“buffer zone” between the Cotter Mill and re sidential homes, ATSDR assumed that very young

children would not access the ar ea. Adolescent and adults woul d access the site infrequently.

Therefore, exposure duration (ED) for an adolescent and adult resident was assumed to be 2 days

per week (or 104 days/year) for 30 years. For average body weight, 57 kg was used for an

adolescent and70 kg was used for an adult.

In this evaluation, the bioavailabil ity from incidental i ngestion of arsenic in soil was assumed to

be 80% because it is protective of health. Cadmium was assumed to be 100% bioavailable,

which is also conservative but protective of health.

Direct Skin (Dermal) Contact with Chemicals in Soil

Dermal absorption of chemicals from soil depends on the area of contact with exposed skin, the

duration of contact, the chemical and physical at traction between the contaminant and soil, the

ability of the chemical to penetr ate the skin, and other factors.

The exposure dose formula for dermal absorptio n of chemicals soil and/or sediment is:

Exposure Dose (ED) = C × SA× AF × ABS × EF × ED × CF

BW ×

AT

Where:

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)

C

= chemical concentration (mg/kg)

SA = surface area exposed (square centimeters/day or cm 2 

### /day)

177Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### AF = soil to skin adherence factor (millig rams per square centimeters or mg/cm 2 

### )

ABS = Absorption factor (unitless)

EF = exposure frequency (days/year)

ED = exposure duration (years)

CF = conversion factor (10 -6 

### kg/mg)

BW = body weight (kg)

AT = averaging time (days)

Note: Absorption factors (ABS) are used to reflec t the desorption of the chemical from soil and

the absorption of the chemical acros s the skin and into the bloodstream.

For the dermal contact pathway, ATSDR assumed that the surface area availa ble in an adolescent

for direct skin contact is 4,300 cubic centimeters per day (cm 2 

### /day); the surface area available in

an adult is 5,000 cm 2 

### /day. An adherence factor of 0.07 milligrams per cubic centimeter (mg/cm 3 

### )

was used. An absorption factor of 0.03 was us ed for arsenic and 0.01 was used for cadmium.

Individuals were assumed to we igh 57 kg as an adolescent and 70 kg as an adult, and to be

exposed for 6 and 30 years, respectively.

The total soil oral and dermal non-carci nogenic dose was estimated as follows:

Total Dose (TD) = ID + DD

Where:

TD = total soil ingestion and dermal non-carcinogenic dose

ID = Soil ingestion non-carci nogenic dose (mg/kg/day)

DD = Soil dermal non-carci nogenic dose (mg/kg/day)

Cancer Risk Estimates

EPA classifies arsenic as a Class A known human carcinogen by the oral and inhalation routes.

Cadmium is classified by EPA as a probable human carcinogen, but only vi a the inhalation route

of exposure. Therefore, only arsenic is evaluated for its carcinogenic risk.

The Lifetime Estimated Cancer Risk for arsenic is estimated as follows:

LECR = TDs x CSF x EF

Where:

LECR = lifetime estimated cancer risk

TDs = total soil oral and dermal non-carcinogenic dose (mg/kg/day)

CSF = cancer slope factor ((mg/kg-day) -1 

### )

EF = Exposure factor (unitless) = exposure dura tion / lifetime = (30 years) / (70 years) = 0.4

The cancer slope factor for arsenic is 1.5 mg/kg-day. Ther efore, the LECR is 1.2 x 10 -5



### .

178Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable C2. Summary of Exposure Factors andExposure Doses for the Soil Exposure Pathway for Chemicals at the Cotter Mill SiteChemicalChemicalConcentration(mg/kg)DailyIntakeRate(mg/day)ExposureFrequency(days/yr)ExposureDuration(years)BodyWeight(kg)AveragingTime(days)Exposure Dose(mg/kg/day)Health Guideline(mg/kg/day)Soil Exposure Pathway: Accidental Ingestion and Direct Skin Contact - ADULT and ADOLESCENTArsenic (ingestion)451001043070109500.000020.0003 MRLArsenic(dermal)NA1043070109500.000002TOTAL DOSE ARSENIC - Adult0.00002Below GuidelineCadmium(ingestion)371001043070109500.000020.0001 MRLCadmium(dermal)NA1043070109500.0000005TOTAL DOSE CADMIUM -Adult0.00002Below GuidelineArsenic (ingestion)4510010465421900.000020.0003 MRLArsenic(dermal)NA10465421900.000002TOTAL DOSE ARSENIC - Adolescent0.00002Below GuidelineCadmium(ingestion)3710010465421900.000020.0001 MRLCadmium(dermal)NA10465421900.0000006TOTAL DOSE CADMIUM - Adolescent0.00002Below Guideline179Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Incidental Ingestion of Chemicals in Surface Water

The ATSDR exposure dose formula used for the ingestion of chemicals in surface water while

wading or swimming is:



### Exposure Dose (ED) = C x IR x ET x EF x ED

BW x AT

Where:

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)

C

= concentration of contaminant in wa ter in milligrams per liter (mg/L)

IR = ingestion rate in liters per day (L/ day); based on contact rate of 50 ml/hr

ET = exposure time (hours/event)

EF = exposure frequency (events/year)

ED = exposure duration (years)

BW = body weight (kg)

AT = averaging time, days (equal to ED fo r non-carcinogens and 70 year lifetime for

carcinogens, i.e., 70 years x 365 days/year)

This pathway assumes that adult and children residents would accidental ly swallow 50 milliliters

of water per hour while swimming, wading or r ecreating in Sand Creek or the DeWeese Dye

Ditch. In terms of exposure time and frequenc y, ATSDR conservatively assumed an adult and

child resident would recreate in these waters for 2 hours pe r day, 2 days per week (or 104

days/year) for 30 years and 6 years, respectivel y. For average body weight, 70 kg and 16 kg were

used for adults and children, respectively.

Direct Skin (Dermal) Contact wi th Chemicals in Surface Water

ATSDR’s exposure dose formula for dermal absorption of chemicals soil and/or sediment is:

Exposure Dose (ED) = C × SA × PC × ET x EF × ED × CF

BW ×

AT

Where:

ED = exposure dose in milligrams per kilogram per day (mg/kg/day)

C

= chemical concen tration (mg/L)

SA = surface area exposed (cm 2 

### )

PC = chemical-specific dermal pe rmeability constant (cm/hr)

ET = exposure time (hours/day)

EF = exposure frequency (days/year)

ED = exposure duration (years)

CF = volumetric conversion factor for water (1L/1000 cm 3 

### )

BW = body weight (kg)

AT = averaging time (days)

180Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### The dermal contact pathway assumes that the total body surface area available for contact with

water is 20,000 cm 2 

### for adults and 9,300 cm 2 

### for children. Adults were assumed to weigh 70 kg

and to be exposed for 30 years. Children were assumed to weigh 16 kg and to be exposed for 6

years. Adults and children were conservatively assumed to swim in the contaminated water 2

days per week (104 days per year) for 2 hours per recreating event. A dermal permeability

constant of 0.001 cm/hr was used for both manganese and molybdenum.

181Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public CommentTable C3. Summary of Exposure Factors andExposure Doses for the Surface Water Pathway for Chemicals at the Cotter Mill SiteChemicalChemicalConcentration(mg/L)DailyIngestionRate(L/day)ExposureFrequency(days/yr)ExposureDuration(yrs)BodyWeight(kg)AveragingTime(days)Exposure Dose(mg/kg/day)HealthGuideline(mg/kg/day)Surface Water Exposure Pathway: Accidental Ingestion and DirectSkin Contact while Wading or Swimming – ADULT and CHILDManganese*Adult Ingestion1.90.11043070109503.9 x 10-40.05Chronic Oral RfDManganeseAdult DermalNA1043070109503.1 x 10-4TOTAL DOSE MANGANESE – Adult7 x 10-4Below GuidelineManganeseChild Ingestion0.110461621901.7 x 10-30.05Chronic Oral RfDManganeseChild DermalNA10461621906.3 x 10-4TOTAL DOSE MANGANESE - Child2.3 x 10-3Below GuidelineMolybdenum†Adult Ingestion0.0510.11043070109501.0 x 10-50.005Chronic Oral RfDMolybdenumAdult DermalNA1043070109508.3 x 10-6TOTAL DOSE MOLYBDENUM - Adult1.8 x 10-5Below GuidelineMolybdenumChild Ingestion0.110461621904.5 x 10-50.005Chronic Oral RfDMolybdenumChild DermalNA10461621901.7 x 10-5TOTAL DOSE MOLYBDENUM - Child6.2 x 10-5Below Guideline*Maximum concentration of manganese in surface water detected in DeWeese Dye Ditch†Maximum concentration of molybdenum insurface water detected in Sand Creek182Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Consumption of Homegrown Fruits and Vegetables

The following formula presents the method for calculating an exposure dose for a typical

consumer of homegrown fruits and vegetables:

Exposure Dose (mg/kg/day) = C x IR x CF

Where:

C

= contaminant concentration (mg/kg)

IR = intake rate of fruit or vegetable (g/kg/day)

CF = conversion factor (1 x 10 -3 

### kg/mg)

Exposure doses for ingestion of garden vegetables were calculated usi ng the average detected

concentration of each contaminant measured in fruit and vegetable samples, in mg/kg, multiplied

by average consumption rates of homegrown fruits or vegetables in grams per kilogram of body

weight per day (g/kg/day). Intake rates were taken from EPA’s Exposure Factors Handbook for

adults, and EPA’s Child-Specific Exposure Factors Handbook for children, for the Western

United States. The average consumption rate was used to represent a “typical” fruit and

vegetable consumer. The 95 percentile consump tion rate was used to represent an “above

average” consumer of fruits and vegetables. The calculated value was multiplied by a conversion

factor of 0.001 kilograms per gram.

183Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Table C4. Summary of Exposure Doses for Lo cal Fruits and Vegetables Irrigated with

Contaminated Well Water

Chemical Chemical

Concentration/

Exposure

Group Exposure Dose

Fruits

(mg/kg/day) Exposure Dose

Vegetables

(mg/kg/day) Health

Guideline

(mg/kg/day)

Arsenic Average consumer 0.0001 0.0001

0.0003, Chronic

Oral MRL Above Average

Consumer 0.0006 0.0005

Child 0.0002 0.0002

Infant 0.0004 0.0004

Barium Average consumer 0.001 0.003

0.2 Chronic Oral

MRL Above Average

Consumer 0.005 0.010

Child 0.002 0.004

Infant 0.004 0.008

Cadmium Average consumer 0.0001 0.0001

0.001, RfD Above Average

Consumer 0.0005 0.0002

Child 0.0002 0.0001

Infant 0.0004 0.0002

Chromium Average consumer 0.0001 0.0001

1.5 RfD Above Average

Consumer 0.0006 0.0003

Child 0.0002 0.0001

Infant 0.0005 0.0003

Cobalt Average consumer ND 0.00004

0.01 Intermediate

MRL Above Average

Consumer ND 0.00012

Child ND 0.00005

Infant ND 0.0001

Lead Average consumer 0.0003 0.0004

NA Above Average

Consumer 0.001 0.001

Child 0.0005 0.0005

Infant 0.001 0.001

Manganese Average consumer 0.002 0.004

0.14 RfD Above Average

Consumer 0.01 0.02

Child 0.004 0.006

Infant 0.008 0.01

Molybdenum Average consumer 0.0003 0.001

0.005 RfD Above Average

Consumer 0.001 0.004

184Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Chemical Chemical

Concentration/

Exposure

Group Exposure Dose

Fruits

(mg/kg/day) Exposure Dose

Vegetables

(mg/kg/day) Health

Guideline

(mg/kg/day)

Child 0.0005 0.002

Infant 0.001 0.004

Nickel Average consumer ND 0.0001

0.02 RfD Above Average

Consumer ND 0.0005

Child ND 0.0002

Infant ND 0.0004

Strontium Average consumer 0.004 0.009

0.6 RfD Above Average

Consumer 0.02 0.03

Child 0.007 0.01

Infant 0.01 0.03

Uranium Average consumer 0.00002 0.00001

0.002 Intermediate

MRL Above Average

Consumer 0.00008 0.00004

Child 0.00003 0.00002

Infant 0.00006 0.00004

Vanadium Average consumer ND 0.00008

0.003 Intermediate

MRL Above Average

Consumer ND 0.0003

Child ND 0.0001

Infant ND 0.0002

Zinc Average consumer 0.004 0.006

0.3 Chronic Oral

MRL Above Average

Consumer 0.02 0.02

Child 0.006 0.008

Infant 0.01 0.02

Bolded text exceeds a health guideline.

ND = not detected

NA = not available

185Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### ATSDR’s Evaluation of Cancer a nd Non-Cancer Health Effects

Non-Cancer Health Effects

The doses calculated for exposure to each indivi dual chemical are compared to an established

health guideline, such as a MRL or RfD, in order to assess whet her adverse health impacts from

exposure are expected. These he alth guidelines, developed by ATSDR and EPA, are chemicalspecific values that are based on the available sc ientific literature and ar e considered protective

of human health. Non-carcinogenic effects, unlike carcinogenic effects, are believed to have a

threshold, that is, a dose below which adverse he alth effects will not occur. As a result, the

current practice for deriving health guidelines is to identify, usually from animal toxicology

experiments, a No Observed Adverse Effect Le vel (or NOAEL), which indicates that no effects

are observed at a particular exposure level. This is the experimental exposure level in animals

(and sometimes humans) at which no adverse toxic effect is observed. The NOAEL is then

modified with an uncertainty (or safety) factor, which reflects the degree of uncertainty that

exists when experimental animal data are ex trapolated to the general human population. The

magnitude of the uncertainty factor considers various factors such as sensitive subpopulations

(for example; children, pregnant women, and the elderly), extrapol ation from animals to humans,

and the completeness of available data. Thus, expos ure doses at or below the established health

guideline are not expected to result in adverse he alth effects because these values are much lower

(and more human health protective) than doses, which do not cause adverse health effects in

laboratory animal studies. For non-cancer health effects, the following health guidelines are

described below in more detail. It is important to consider th at the methodology used to develop

these health guidelines does not provide any information on the presence, absence, or level of

cancer risk. Therefore, a separate cancer eval uation is necessary for potentially cancer-causing

chemicals detected in samples at this site. A mo re detailed discussion of the evaluation of cancer

risks is presented in the following section.

Minimal Risk Levels (MRLs) – developed by ATSDR

ATSDR has developed MRLs for contaminants commonly found at hazardous waste sites. The

MRL is an estimate of daily exposure to a co ntaminant below which non-cancer, adverse health

effects are unlikely to occur. MRLs are developed for different routes of exposure, such as

inhalation and ingestion, and for lengths of e xposure, such as acute (less than 14 days),

intermediate (15-364 days), and chronic (365 days or greater). At this time, ATSDR has not

developed MRLs for dermal exposure. A complete list of the available MRLs can be found at

http://www.atsdr.cdc.gov/mrls.html

.

References Doses (RfDs) – developed by EPA

An estimate of the daily, lifetime exposure of human populations to a possibl e hazard that is not

likely to cause non-cancerous he alth effects. RfDs consider exposures to sensitive subpopulations, such as the elderly, children, and th e developing fetus. EPA RfDs have been

developed using information from the available scie ntific literature and have been calculated for

oral and inhalation exposures. A complete li st of the available RfDs can be found at

http://www.epa.gov/iris

.

186Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### If the estimated exposure dose for a chemical is le ss than the health guideline value, the exposure

is unlikely to result in non-cance r health effects. Non-cancer hea lth effects from dermal exposure

were evaluated slightly differently that ingesti on and inhalation exposure. Since health guidelines

are not available for dermal exposure, the calcul ated dermal dose was compared with the oral

health guideline value (RfD or MRL).

If the calculated exposure dose is greater than the health guideline, the exposure dose is

compared to known toxicological values for the pa rticular chemical and is discussed in more

detail in the text of the PHA. The known toxicological values are doses derived from human and

animal studies that are presented in the ATSD R Toxicological Profiles and EPA’s Integrated

Information System (IRIS). A direct comparison of site-specific exposure doses to study-derived

exposures and doses found to cause adverse heal th effects is the basis for deciding whether

health effects are likely to occur. This in-dep th evaluation is performed by comparing calculated

exposure doses with known toxicological values, such as the no-observed adverse-effect-level

(NOAEL) and the lowest-observed-adverse-effect-l evel (LOAEL) from studies used to derive

the MRL or RfD for a chemical.

Cancer Risks

Exposure to a cancer-causing compound, even at low concentrations, is assumed to be associated

with some increased risk for evaluation purposes. The estimated excess risk of developing cancer

from exposure to contaminants associated with the site was calculated by multiplying the sitespecific adult exposure doses, with a slight modification, by EPA’s chemical-specific Cancer

Slope Factors (CSFs or cancer potenc y estimates), which are available at

http://www.epa.gov/iris

. Calculated dermal doses were compared with the oral CSFs.

An increased excess lifetime cancer risk is not a sp ecific estimate of expected cancers. Rather, it

is an estimate of the increase in the probabi lity that a person may develop cancer sometime

during his or her lifetime following exposure to a particular contaminant. Therefore, the cancer

risk calculation incorporates the equations and parameters (including the exposure duration and

frequency) used to calculate the dose estimat es, but the estimated value is divided by 25,550

days (or the averaging time), which is equal to a lifetime of exposure (70 years) for 365

days/year.

There are varying suggestions among the scientific community regarding an acceptable excess

lifetime cancer risk, due to the uncertaintie s regarding the mechanism of cancer. The

recommendations of many scientists and EPA have been in the risk range of 1 in 1 million to 1 in

-6 -4 

### 10,000 (as referred to as 1 x 10 to 1 x 10 ) excess cancer cases. An increased lifetime cancer

risk of one in one million or less is generally co nsidered an insignificant increase in cancer risk.

-5 

### Cancer risk less than 1 in 10,000 (or 1 x 10 ) are not typically consider ed a health concern. An

important consideration when determining cancer ri sk estimates is that the risk calculations

incorporate several very conservative assumptions that are expected to overestimate actual

exposure scenarios. For example, the method used to calculate EPA’s CSFs assumes that highdose animal data can be used to estimate th e risk for low dose exposures in humans. As

previously stated, the method also assumes that there is no safe level for exposure. Lastly, the

187Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### method computes the 95% upper bound for the risk, rather than the average risk, suggesting that

the cancer risk is actually lower, perhaps by several orders of magnitude.

Because of the uncertainties i nvolved with estimating carcin ogenic risk, ATSDR employs a

weight-of-evidence approach in evaluating all rele vant data. Therefore, the carcinogenic risk is

also described in words (qualita tively) rather than giving a nu merical risk estimate only. The

numerical risk estimate must be considered in the context of the variables and assumptions

involved in their derivation and in the broader context of biom edical opinion, host factors, and

actual exposure conditions. The actual parameters of environmental exposures have been given

careful and thorough consideration in evaluating the assumptions and variables relating to both

toxicity and exposure. A complete review of the toxicological data regarding the doses

associated with the production of cancer and the site-specific doses for the site is an important

element in determining the likelihood of exposed individuals being at a gr eater risk for cancer.

188Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



## Appendix D. ATSDR Glossary of Environmental Health Terms

The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health

agency with headquarters in A tlanta, Georgia, and 10 regional offices in the United States.

ATSDR’s mission is to serve th e public by using the best scie nce, taking responsive public

health actions, and providing trusted health information to prevent harmful exposures and

diseases related to toxic subs tances. ATSDR is not a regula tory agency, unlike the U.S.

Environmental Protection Agency (EPA), which is the federal agency that develops and enforces

environmental laws to protect th e environment and human health.

This glossary defines words used by ATSDR in communications with th e public. It is not a

complete dictionary of environmental health terms. If you have questions or comments, call

ATSDR’s toll-free telephone number, 1-800-CDC-INFO (1-800-232-4636).

Absorption

The process of taking in. For a person or an an imal, absorption is the process of a substance

getting into the body through the eyes, sk in, stomach, intestines, or lungs.

Acute

Occurring over a short time [compare with chronic].

Acute exposure

Contact with a substance that occurs once or fo r only a short time (up to 14 days) [compare with

intermediate duration exposur e and chronic exposure].

Additive effect

A biologic response to exposure to multiple substances that equals the sum of responses of all the

individual substances added togeth er [compare with antagonistic e ffect and synergistic effect].

Adverse health effect

A change in body function or cell structure that might lead to disease or health problems

Aerobic

Requiring oxygen [compare with anaerobic].

Ambient

Surrounding (for example, ambient air).

Anaerobic

Requiring the absence of oxygen [compare with aerobic].

Analyte

A substance measured in the laboratory. A chemical for which a sample (such as water, air, or

blood) is tested in a laboratory. For example, if the analyte is mercury, the laboratory test will

determine the amount of mercury in the sample.

189Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Analytic epidemiologic study

A study that evaluates the association between exposure to hazardous substances and disease by

testing scientif ic hypotheses.

Antagonistic effect

A biologic response to exposure to multiple substances that is less than would be expected if the

known effects of the individual substances were added together [compare with additive effect

and synergistic effect].

Background level

An average or expected amount of a substance or radioactive mate rial in a specific environment,

or typical amounts of substances that occur naturally in an environment.

Biodegradation

Decomposition or breakdown of a substance th rough the action of micr oorganisms (such as

bacteria or fungi) or other natural phys ical processes (such as sunlight).

Biologic indicators of exposure study

A study that uses (a) biomedical testing or (b) the measurement of a substance [an analyte], its

metabolite, or another marker of exposure in human body fluids or tissues to confirm human

exposure to a hazardous substance [als o see exposure investigation].

Biologic monitoring

Measuring hazardous substances in biologic materi als (such as blood, hair, urine, or breath) to

determine whether exposure has oc curred. A blood test for lead is an example of biologic

monitoring.

Biologic uptake

The transfer of substances from the envi ronment to plants, animals, and humans.

Biomedical testing

Testing of persons to find out whether a chan ge in a body function might have occurred because

of exposure to a hazardous substance.

Biota

Plants and animals in an environment. Some of these plants and animals might be sources of

food, clothing, or medicines for people.

Body burden

The total amount of a substance in the body. Some substances build up in the body because they

are stored in fat or bone or because they leave the body very slowly.

CAP [see Community Assistance Panel.]

Cancer

Any one of a group of diseases that occur when cells in the body become abnormal and grow or

multiply out of control.

190Public Health Assessment, Lincoln Park/Cotter Uranium Mill Superfund Site, Public Comment



### Cancer risk

A theoretical risk for getting can cer if exposed to a substance ev ery day for 70 years (a lifetime

exposure). The true risk might be lower.

Carcinogen

A substance that causes cancer.

Case study

A medical or epidemiologic evaluation of one person or a small group of people to gather

information about specific health conditions and past exposures.

Case-control study

A study that compares exposures of people who ha ve a disease or condition (cases) with people

who do not have the disease or condition (controls). E xposures that are more common among the

cases may be considered as possible risk factors for the disease.

CAS registry number

A unique number assigned to a substance or mixture by the American Chemical Society

Abstracts Service.

Central nervous system

The part of the nervous system that cons ists of the brain and the spinal cord.

CERCLA [see Comprehensive Environmental Respons e, Compensation, and Liability Act of

1980]

Chronic

Occurring over a long time [compare with acute].

Chronic exposure

Contact with a substance that occurs over a l ong time (more than 1 year) [compare with acute

exposure and intermediate duration exposure]

Cluster investigation

A review of an unusual number, r eal or perceived, of health ev ents (for example, reports of

cancer) grouped together in time and location. Cluster investiga tions are designed to confirm

case reports; determine whether they represent an unusual disease occurrence; and, if possible,

explore possible causes and contri buting environmental factors.

Community Assistance Panel (CAP)

A group of people from a community and from h ealth and environmental agencies who work

with ATSDR to resolve issues and problems rela ted to hazardous substances in the community.

CAP members work with ATSDR to gather and review commun ity health concerns, provide

information on how people might have been or might now be exposed to hazardous substances,

and inform ATSDR on ways to involve the community in its activities.

Comparison value (CV)

Calculated concentration of a substance in air, water, food, or soil that is unlikely to cause

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### harmful (adverse) health effects in exposed peop le. The CV is used as a screening level during

the public health assessment process. Substanc es found in amounts greater than their CVs might

be selected for further evaluation in the public health assessment process.

Completed exposure pathway [see exposure pathway].

Comprehensive Environmental Response, Compensation, and Liability Act of 1980

(CERCLA)

CERCLA, also known as Superfund, is the federal law that concerns the removal or cleanup of

hazardous substances in the environment and at hazardous waste sites. ATSDR, which was

created by CERCLA, is responsible for assessi ng health issues and supporting public health

activities related to hazardous waste sites or other environmental releases of hazardous

substances. This law was later amended by the Superfund Amendments and Reauthorization Act

(SARA).

Concentration

The amount of a substance present in a certain amount of soil, wate r, air, food, blood, hair, urine,

breath, or any other media.

Contaminant

A substance that is either presen t in an environment where it do es not belong or is present at

levels that might cause harmfu l (adverse) health effects.

Delayed health effect

A disease or an injury that happens as a result of exposur es that might have occurred in the past.

Dermal

Referring to the skin. For example, dermal absorption means passing through the skin.

Dermal contact

Contact with (touching) the skin [see route of exposure].

Descriptive epidemiology

The study of the amount and distribution of a di sease in a specified popul ation by person, place,

and time.

Detection limit

The lowest concentration of a chemical that can reliably be distinguished from a zero

concentration.

Disease prevention

Measures used to prevent a di sease or reduce its severity.

Disease registry

A system of ongoing registration of all cases of a particular di sease or health condition in a

defined population.

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### DOD

United States Department of Defense.

DOE

United States Department of Energy.

Dose (for chemicals that are not radioactive)

The amount of a substance to which a person is exposed over some time period. Dose is a

measurement of exposure. Dose is often expr essed as milligram (amount) per kilogram (a

measure of body weight) per day (a measure of time) when people eat or drink contaminated

water, food, or soil. In general, the greater the dose, the greater the like lihood of an effect. An

“exposure dose” is how much of a substance is encountered in the environment. An “absorbed

dose” is the amount of a substa nce that actually got into the body through the eyes, skin,

stomach, intestines, or lungs.

Dose (for radioactive chemicals)

The radiation dose is the amount of energy from radiation that is actually absorbed by the body.

This is not the same as measurements of th e amount of radiation in the environment.

Dose-response relationship

The relationship between the amount of exposure [ dose] to a substance a nd the resulting changes

in body function or health (response).

Environmental media

Soil, water, air, biota (plants a nd animals), or any other parts of the environment that can contain

contaminants.

Environmental media and transport mechanism

Environmental media include wa ter, air, soil, an d biota (plants and animals). Transport

mechanisms move contaminants from the source to points where human exposure can occur. The

environmental media and transport mechanism is the second part of an exposure pathway.

EPA

United States Environmental Protection Agency.

Epidemiologic surveillance [see Public health surveillance].

Epidemiology

The study of the distribution and determinants of disease or health status in a population; the

study of the occurrence and causes of health effects in humans.

Exposure

Contact with a substance by swallowing, breathing, or touching the skin or eyes. Exposure may

be short-term [acute exposure], of intermedia te duration, or long-term [chronic exposure].

Exposure assessment

The process of finding out how people come into contact with a hazardous substance, how often

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### and for how long they are in contact with the subs tance, and how much of the substance they are

in contact with.

Exposure-dose reconstruction

A method of estimating the amount of people’s past exposure to hazardous substances. Computer

and approximation methods are used when past in formation is limited, not available, or missing.

Exposure investigation

The collection and analysis of site-specific info rmation and biologic tests (when appropriate) to

determine whether people have been exposed to hazardous substances.

Exposure pathway

The route a substance takes from its source (where it began) to its end point (where it ends), and

how people can come into contact with (or get exposed to) it. An exposure pathway has five

parts: a source of contamination (such as an abandoned business); an environmental media and

transport mechanism (such as movement through groundwater); a point of exposure (such as a

private well); a route of exposure (eating, drin king, breathing, or touc hing), and a receptor

population (people potentially or act ually exposed). When all five parts are present, the exposure

pathway is termed a completed exposure pathway.

Exposure registry

A system of ongoing followup of people who have had documented environmental exposures.

Feasibility study

A study by EPA to determine the best way to cl ean up environmental contamination. A number

of factors are considered, including health ri sk, costs, and what methods will work well.

Geographic information system (GIS)

A mapping system that uses computers to collect, store, manipulate, anal yze, and display data.

For example, GIS can show the concentration of a contaminant within a community in relation to

points of reference such as streets and homes.

Grand rounds

Training sessions for physicia ns and other health care provi ders about health topics.

Groundwater

Water beneath the earth’s surface in the spaces betw een soil particles and between rock surfaces

[compare with surface water].

Half-life (t1⁄2)

The time it takes for half the original amount of a substance to disappear. In the environment, the

half-life is the time it takes for half the original amount of a s ubstance to disappear when it is

changed to another chemical by b acteria, fungi, sunlight, or othe r chemical processes. In the

human body, the half-life is the time it takes for half the original amount of the substance to

disappear, either by being changed to another su bstance or by leaving the body. In the case of

radioactive material, the half life is the amount of time necessary for one half the initial number

of radioactive atoms to change or transform into another atom (that is normally not radioactive).

After two half lives, 25% of the original number of radioactive atoms remain.

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### Hazard

A source of potential harm from pa st, current, or future exposures.

Hazardous Substance Release and Health Effects Database (HazDat)

The scientific and administrative database system developed by ATSDR to manage data

collection, retrieval, and anal ysis of site-specific inform ation on hazardous substances,

community health concerns, a nd public health activities.

Hazardous waste

Potentially harmful substances that have been released or discarded into the environment.

Health consultation

A review of available information or collecti on of new data to respond to a specific health

question or request for information about a poten tial environmental hazard. Health consultations

are focused on a specific exposure issue. Health c onsultations are therefore more limited than a

public health assessment, which reviews the expo sure potential of each pathway and chemical

[compare with public health assessment].

Health education

Programs designed with a community to help it k now about health risks and how to reduce these

risks.

Health investigation

The collection and evaluation of information about the health of community residents. This

information is used to describe or count the occurrence of a disease, symptom, or clinical

measure and to evaluate the possible associ ation between the occu rrence and exposure to

hazardous substances.

Health promotion

The process of enabling people to increase c ontrol over, and to improve, their health.

Health statistics review

The analysis of existing health information (i.e., from death certi ficates, birth defects registries,

and cancer registries) to determin e if there is excess disease in a specific population, geographic

area, and time period. A health statistics re view is a descriptive epidemiologic study.

Indeterminate public health hazard

The category used in ATSDR’s public health assessment documents when a professional

judgment about the level of health hazard cannot be made because information critical to such a

decision is lacking.

Incidence

The number of new cases of disease in a defined population over a specific time period [contrast

with prevalence].

Ingestion

The act of swallowing something through eating, drinking, or mouthing objects. A hazardous

substance can enter the body this way [see route of exposure].

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### Inhalation

The act of breathing. A hazardous substance can ente r the body this way [see route of exposure].

Intermediate duration exposure

Contact with a substance that o ccurs for more than 14 days and less than a year [compare with

acute exposure and chronic exposure].

In vitro

In an artificial environment outside a living or ganism or body. For example, some toxicity

testing is done on cell cultures or slices of tissue grown in the la boratory, rather than on a living

animal [compare with in vivo].

In vivo

Within a living organism or body. For example, some toxicity testing is done on whole animals,

such as rats or mice [com pare with in vitro].

Lowest-observed-adverse-effect level (LOAEL)

The lowest tested dose of a substance that has been reported to cause harmful (adverse) health

effects in people or animals.

Medical monitoring

A set of medical tests and physical exams speci fically designed to evaluate whether an

individual’s exposure co uld negatively affect that person’s health.

Metabolism

The conversion or breakdown of a substance from one form to another by a living organism.

Metabolite

Any product of metabolism.

mg/kg

Milligram per kilogram.

mg/cm 2



### Milligram per square centimeter (of a surface).

mg/m 3



### Milligram per cubic meter; a measure of the co ncentration of a chemical in a known volume (a

cubic meter) of air, soil, or water.

Migration

Moving from one location to another.

Minimal risk level (MRL)

An ATSDR estimate of daily human exposure to a hazardous substance at or below which that

substance is unlikely to pose a measurable risk of harmful (adverse), noncancerous effects.

MRLs are calculated for a route of exposure (inhalation or oral) over a specified time period

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### (acute, intermediate, or chronic). MRLs should not be used as predictors of harmful (adverse)

health effects [see reference dose].

Morbidity

State of being ill or diseased. Morbidity is the occurrence of a disease or condition that alters

health and quality of life.

Mortality

Death. Usually the cause (a sp ecific disease, a condition, or an injury) is stated.

Mutagen

A substance that causes muta tions (genetic damage).

Mutation

A change (damage) to the DNA, genes, or chromosomes of living organisms.

National Priorities List for Uncontrolled Hazard ous Waste Sites (National Priorities List or

NPL)

EPA’s list of the most serious uncontrolled or abandoned hazardous wast e sites in the United

States. The NPL is updated on a regular basis.

National Toxicology Program (NTP)

Part of the Department of Health and Human Se rvices. NTP develops an d carries out tests to

predict whether a chemical wi ll cause harm to humans.

No apparent public health hazard

A category used in ATSDR’s public health a ssessments for sites where human exposure to

contaminated media might be occu rring, might have occurred in th e past, or might occur in the

future, but where the exposure is not expected to cause any harmful health effects.

No-observed-adverse-effect level (NOAEL )

The highest tested dose of a substance that has b een reported to have no harmful (adverse) health

effects on people or animals.

No public health hazard

A category used in ATSDR’s public health asse ssment documents for sites where people have

never and will never come into contact with harmful amounts of site-related substances.

NPL [see National Priorities List for Uncontrolled Hazardous Waste Sites]

Physiologically based pharmacokinetic model (PBPK model)

A computer model that describes what happens to a chemical in the body. This model describes

how the chemical gets into the body, where it goes in the body, how it is changed by the body,

and how it leaves the body.

Pica

A craving to eat nonfood items, such as dirt, pain t chips, and clay. Some children exhibit picarelated behavior.

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### Plume

A volume of a substance that moves from its s ource to places farther away from the source.

Plumes can be described by the volume of air or water they occupy and th e direction they move.

For example, a plume can be a column of smok e from a chimney or a substance moving with

groundwater.

Point of exposure

The place where someone can come into contact with a substance present in the environment

[see exposure pathway].

Population

A group or number of people livi ng within a specified area or sh aring similar characteristics

(such as occupation or age).

Potentially responsible party (PRP)

A company, government, or pe rson legally responsible for cleaning up the pollution at a

hazardous waste site under Superfund. There may be more than one PRP for a particular site.

ppb

Parts per billion.

ppm

Parts per million.

Prevalence

The number of existing disease cases in a de fined population during a specific time period

[contrast with incidence].

Prevalence survey

The measure of the current level of disease(s) or symptoms and exposures through a

questionnaire that collects self-reported information from a defined population.

Prevention

Actions that reduce exposure or ot her risks, keep people from gett ing sick, or keep disease from

getting worse.

Public availability session

An informal, drop-by meeting at which commun ity members can meet one-on-one with ATSDR

staff members to discuss hea lth and site-related concerns.

Public comment period

An opportunity for the public to comment on agen cy findings or proposed activities contained in

draft reports or documents. The public commen t period is a limited time period during which

comments will be accepted.

Public health action

A list of steps to protect public health.

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### Public health advisory

A statement made by ATSDR to EPA or a state re gulatory agency that a release of hazardous

substances poses an immediate threat to hum an health. The advisory includes recommended

measures to reduce exposure and reduce the threat to human health.

Public health assessment (PHA)

An ATSDR document that examines hazardous s ubstances, health outcomes, and community

concerns at a hazardous waste site to determin e whether people could be harmed from coming

into contact with those substances. The PHA also lists actions that need to be taken to protect

public health [compare with health consultation].

Public health hazard

A category used in ATSDR’s public health assessments for sites that pose a public health hazard

because of long-term exposures (greater than 1 year) to sufficiently high levels of hazardous

substances or radionuclides that could result in harmful health effects.

Public health hazard categories

Public health hazard categories are statemen ts about whether people could be harmed by

conditions present at the site in the past, presen t, or future. One or more hazard categories might

be appropriate for each site. The five public health hazard categorie s are no public health hazard,

no apparent public health hazard, indeterminate public health hazard, public health hazard, and

urgent public health hazard.

Public health statement

The first chapter of an ATSDR toxicological prof ile. The public health statement is a summary

written in words that are easy to understand. The public health statement explains how people

might be exposed to a specific substance and describes the known hea lth effects of that

substance.

Public health surveillance

The ongoing, systematic collection, analysis, and inte rpretation of health data. This activity also

involves timely dissemination of the data and use for public health programs.

Public meeting

A public forum with community member s for communication about a site.

Radioisotope

An unstable or radioactive isotop e (form) of an element that can change into another element by

giving off radiation.

Radionuclide

Any radioactive isotope (f orm) of any element.

RCRA [see Resource Conservation a nd Recovery Act (1976, 1984)]

Receptor population

People who could come into contact with haza rdous substances [see exposure pathway].

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### Reference dose (RfD)

An EPA estimate, with uncertainty or safety f actors built in, of the daily lifetime dose of a

substance that is unlikely to cause harm in humans.

Registry

A systematic collection of information on pers ons exposed to a specific substance or having

specific diseases [see exposure registry and disease registry].

Remedial investigation

The CERCLA process of determining the type and ex tent of hazardous material contamination at

a site.

Resource Conservation and Recovery Act (1976, 1984) (RCRA)

This Act regulates management and disposal of hazardous wastes currently generated, treated,

stored, disposed of, or distributed.

RFA

RCRA Facility Assessment. An assessment requi red by RCRA to identify potential and actual

releases of hazardous chemicals.

RfD [see reference dose]

Risk

The probability that something will cause injury or harm.

Risk reduction

Actions that can decrease the like lihood that individuals , groups, or communities will experience

disease or other health conditions.

Risk communication

The exchange of information to incr ease understanding of health risks.

Route of exposure

The way people come into contact with a hazardous substance. Three routes of exposure are

breathing [inhalation], eating or drinking [ingestion], or contact with the skin [dermal contact].

Safety factor [see uncertainty factor]

SARA [see Superfund Amendments a nd Reauthorization Act]

Sample

A portion or piece of a whole. A selected subset of a population or subset of whatever is being

studied. For example, in a study of people the sample is a number of people chosen from a larger

population [see population]. An environmental sample (for example, a small amount of soil or

water) might be collected to measure contamination in the environment at a specific location.

Sample size

The number of units chosen from a population or an environment.

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### Solvent

A liquid capable of dissolving or dispersing anot her substance (for example, acetone or mineral

spirits).

Source of contamination

The place where a hazardous substance comes from, such as a landfill, waste pond, incinerator,

storage tank, or drum. A source of contamination is the first part of an exposure pathway.

Special populations

People who might be more sensitiv e or susceptible to exposure to hazardous substances because

of factors such as age, occupation, sex, or beha viors (for example, cigarette smoking). Children,

pregnant women, and older people are of ten considered special populations.

Stakeholder

A person, group, or community who has an interest in activities at a hazardous waste site.

Statistics

A branch of mathematics that deals with co llecting, reviewing, summarizing, and interpreting

data or information. Statistics are used to determine whether differences between study groups

are meaningful.

Substance

A chemical.

Substance-specific applied research

A program of research designed to fill important data needs for specific hazardous substances

identified in ATSDR’s toxicological profiles. Fill ing these data needs would allow more accurate

assessment of human risks from specific substa nces contaminating the environment. This

research might include human st udies or laboratory experiments to determine health effects

resulting from exposure to a given hazardous substance.

Superfund [see Comprehensive Environmental Respons e, Compensation, and Liability Act of

1980 (CERCLA) and Superfund Amendments and Reauthorization Act (SARA)]

Superfund Amendments and Reauthorization Act (SARA)

In 1986, SARA amended the Comprehensive Environmental Response, Compensation, and

Liability Act of 1980 (CERCLA) and expanded the health-related respons ibilities of ATSDR.

CERCLA and SARA direct ATSDR to look into th e health effects from substance exposures at

hazardous waste sites and to perform activities including health education, health studies,

surveillance, health consultations , and toxicological profiles.

Surface water

Water on the surface of the earth, such as in lake s, rivers, streams, ponds, and springs [compare

with groundwater].

Surveillance [see public health surveillance]

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### Survey

A systematic collection of information or data. A survey can be conducted to collect information

from a group of people or from the environment. Surveys of a group of people can be conducted

by telephone, by mail, or in person. Some surv eys are done by interviewing a group of people

[see prevalence survey].

Synergistic effect

A biologic response to multiple substances where one substance worsens the effect of another

substance. The combined effect of the substances acting together is grea ter than the sum of the

effects of the substances acting by themselves [see additive eff ect and antagonistic effect].

Teratogen

A substance that causes defects in developmen t between conception and birth. A teratogen is a

substance that causes a structural or functional birth defect.

Toxic agent

Chemical or physical (for example, radiation, he at, cold, microwaves) agents that, under certain

circumstances of exposure, can cause ha rmful effects to living organisms.

Toxicological profile

An ATSDR document that examines, summarizes, and interprets information about a hazardous

substance to determine harmful levels of exposure and associated health effects. A toxicological

profile also identifies significant gaps in know ledge on the substance and describes areas where

further research is needed.

Toxicology

The study of the harmful effects of substances on humans or animals.

Tumor

An abnormal mass of tissue that results from ex cessive cell division th at is uncontrolled and

progressive. Tumors perform no us eful body function. Tumors can be either benign (not cancer)

or malignant (cancer).

Uncertainty factor

Mathematical adjustments for r easons of safety when knowledge is incomplete. For example,

factors used in the calculation of doses that are not harmful (adverse) to people. These factors are

applied to the lowest-observed-adverse-effect-l evel (LOAEL) or the no-observed-adverse-effectlevel (NOAEL) to derive a minima l risk level (MRL). Uncertainty factors are used to account for

variations in people’s sensitivity, for differe nces between animals and humans, and for

differences between a LOAEL and a NOAEL. Scientis ts use uncertainty factors when they have

some, but not all, the information from animal or human studies to deci de whether an exposure

will cause harm to people [also sometimes called a safety factor].

Urgent public health hazard

A category used in ATSDR’s public health asse ssments for sites where short-term exposures

(less than 1 year) to hazardous substances or cond itions could result in harmful health effects that

require rapid intervention.

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### Volatile organic compounds (VOCs)

Organic compounds that evaporate readily into the air. VOCs include substances such as

benzene, toluene, methylene chlo ride, and methyl chloroform.

Other glossaries and dictionaries:

Environmental Protection Agency ( http://www.epa.gov/OCEPAterms / )

National Library of Medicine (NIH)

( http://www.nlm.nih.gov/medlin eplus/mplusdictionary.html )

203